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;;; python.el --- Python's flying circus support for Emacs -*- lexical-binding: t -*-
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;; Copyright (C) 2003-2018 Free Software Foundation, Inc.
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;; Author: Fabián E. Gallina <fgallina@gnu.org>
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;; URL: https://github.com/fgallina/python.el
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;; Version: 0.26.1
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;; Package-Requires: ((emacs "24.1") (cl-lib "1.0"))
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;; Maintainer: emacs-devel@gnu.org
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;; Created: Jul 2010
;; Keywords: languages

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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published
;; by the Free Software Foundation, either version 3 of the License,
;; or (at your option) any later version.
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;; GNU Emacs is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
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;;; Commentary:

;; Major mode for editing Python files with some fontification and
;; indentation bits extracted from original Dave Love's python.el
;; found in GNU/Emacs.

;; Implements Syntax highlighting, Indentation, Movement, Shell
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;; interaction, Shell completion, Shell virtualenv support, Shell
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;; package support, Shell syntax highlighting, Pdb tracking, Symbol
;; completion, Skeletons, FFAP, Code Check, Eldoc, Imenu.
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;; Syntax highlighting: Fontification of code is provided and supports
;; python's triple quoted strings properly.

;; Indentation: Automatic indentation with indentation cycling is
;; provided, it allows you to navigate different available levels of
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;; indentation by hitting <tab> several times.  Also electric-indent-mode
;; is supported such that when inserting a colon the current line is
;; dedented automatically if needed.
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;; Movement: `beginning-of-defun' and `end-of-defun' functions are
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;; properly implemented.  There are also specialized
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;; `forward-sentence' and `backward-sentence' replacements called
;; `python-nav-forward-block', `python-nav-backward-block'
;; respectively which navigate between beginning of blocks of code.
;; Extra functions `python-nav-forward-statement',
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;; `python-nav-backward-statement',
;; `python-nav-beginning-of-statement', `python-nav-end-of-statement',
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;; `python-nav-beginning-of-block', `python-nav-end-of-block' and
;; `python-nav-if-name-main' are included but no bound to any key.  At
;; last but not least the specialized `python-nav-forward-sexp' allows
;; easy navigation between code blocks.  If you prefer `cc-mode'-like
;; `forward-sexp' movement, setting `forward-sexp-function' to nil is
;; enough, You can do that using the `python-mode-hook':
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;; (add-hook 'python-mode-hook
;;           (lambda () (setq forward-sexp-function nil)))
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;; Shell interaction: is provided and allows opening Python shells
;; inside Emacs and executing any block of code of your current buffer
;; in that inferior Python process.

;; Besides that only the standard CPython (2.x and 3.x) shell and
;; IPython are officially supported out of the box, the interaction
;; should support any other readline based Python shells as well
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;; (e.g. Jython and PyPy have been reported to work).  You can change
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;; your default interpreter and commandline arguments by setting the
;; `python-shell-interpreter' and `python-shell-interpreter-args'
;; variables.  This example enables IPython globally:

;; (setq python-shell-interpreter "ipython"
;;       python-shell-interpreter-args "-i")

;; Using the "console" subcommand to start IPython in server-client
;; mode is known to fail intermittently due a bug on IPython itself
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;; (see URL `https://debbugs.gnu.org/cgi/bugreport.cgi?bug=18052#27').
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;; There seems to be a race condition in the IPython server (A.K.A
;; kernel) when code is sent while it is still initializing, sometimes
;; causing the shell to get stalled.  With that said, if an IPython
;; kernel is already running, "console --existing" seems to work fine.

;; Running IPython on Windows needs more tweaking.  The way you should
;; set `python-shell-interpreter' and `python-shell-interpreter-args'
;; is as follows (of course you need to modify the paths according to
;; your system):

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;; (setq python-shell-interpreter "C:/Python27/python.exe"
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;;       python-shell-interpreter-args
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;;       "-i C:/Python27/Scripts/ipython-script.py")
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;; Missing or delayed output used to happen due to differences between
;; Operating Systems' pipe buffering (e.g. CPython 3.3.4 in Windows 7.
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;; See URL `https://debbugs.gnu.org/cgi/bugreport.cgi?bug=17304').  To
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;; avoid this, the `python-shell-unbuffered' defaults to non-nil and
;; controls whether `python-shell-calculate-process-environment'
;; should set the "PYTHONUNBUFFERED" environment variable on startup:
;; See URL `https://docs.python.org/3/using/cmdline.html#cmdoption-u'.
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;; The interaction relies upon having prompts for input (e.g. ">>> "
;; and "... " in standard Python shell) and output (e.g. "Out[1]: " in
;; IPython) detected properly.  Failing that Emacs may hang but, in
;; the case that happens, you can recover with \\[keyboard-quit].  To
;; avoid this issue, a two-step prompt autodetection mechanism is
;; provided: the first step is manual and consists of a collection of
;; regular expressions matching common prompts for Python shells
;; stored in `python-shell-prompt-input-regexps' and
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;; `python-shell-prompt-output-regexps', and dir-local friendly vars
;; `python-shell-prompt-regexp', `python-shell-prompt-block-regexp',
;; `python-shell-prompt-output-regexp' which are appended to the
;; former automatically when a shell spawns; the second step is
;; automatic and depends on the `python-shell-prompt-detect' helper
;; function.  See its docstring for details on global variables that
;; modify its behavior.
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;; Shell completion: hitting tab will try to complete the current
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;; word.  The two built-in mechanisms depend on Python's readline
;; module: the "native" completion is tried first and is activated
;; when `python-shell-completion-native-enable' is non-nil, the
;; current `python-shell-interpreter' is not a member of the
;; `python-shell-completion-native-disabled-interpreters' variable and
;; `python-shell-completion-native-setup' succeeds; the "fallback" or
;; "legacy" mechanism works by executing Python code in the background
;; and enables auto-completion for shells that do not support
;; receiving escape sequences (with some limitations, i.e. completion
;; in blocks does not work).  The code executed for the "fallback"
;; completion can be found in `python-shell-completion-setup-code' and
;; `python-shell-completion-string-code' variables.  Their default
;; values enable completion for both CPython and IPython, and probably
;; any readline based shell (it's known to work with PyPy).  If your
;; Python installation lacks readline (like CPython for Windows),
;; installing pyreadline (URL `http://ipython.org/pyreadline.html')
;; should suffice.  To troubleshoot why you are not getting any
;; completions, you can try the following in your Python shell:
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;; >>> import readline, rlcompleter

;; If you see an error, then you need to either install pyreadline or
;; setup custom code that avoids that dependency.
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;; Shell virtualenv support: The shell also contains support for
;; virtualenvs and other special environment modifications thanks to
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;; `python-shell-process-environment' and `python-shell-exec-path'.
;; These two variables allows you to modify execution paths and
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;; environment variables to make easy for you to setup virtualenv rules
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;; or behavior modifications when running shells.  Here is an example
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;; of how to make shell processes to be run using the /path/to/env/
;; virtualenv:

;; (setq python-shell-process-environment
;;       (list
;;        (format "PATH=%s" (mapconcat
;;                           'identity
;;                           (reverse
;;                            (cons (getenv "PATH")
;;                                  '("/path/to/env/bin/")))
;;                           ":"))
;;        "VIRTUAL_ENV=/path/to/env/"))
;; (python-shell-exec-path . ("/path/to/env/bin/"))

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;; Since the above is cumbersome and can be programmatically
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;; calculated, the variable `python-shell-virtualenv-root' is
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;; provided.  When this variable is set with the path of the
;; virtualenv to use, `process-environment' and `exec-path' get proper
;; values in order to run shells inside the specified virtualenv.  So
;; the following will achieve the same as the previous example:

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;; (setq python-shell-virtualenv-root "/path/to/env/")
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;; Also the `python-shell-extra-pythonpaths' variable have been
;; introduced as simple way of adding paths to the PYTHONPATH without
;; affecting existing values.

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;; Shell package support: you can enable a package in the current
;; shell so that relative imports work properly using the
;; `python-shell-package-enable' command.

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;; Shell remote support: remote Python shells are started with the
;; correct environment for files opened remotely through tramp, also
;; respecting dir-local variables provided `enable-remote-dir-locals'
;; is non-nil.  The logic for this is transparently handled by the
;; `python-shell-with-environment' macro.

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;; Shell syntax highlighting: when enabled current input in shell is
;; highlighted.  The variable `python-shell-font-lock-enable' controls
;; activation of this feature globally when shells are started.
;; Activation/deactivation can be also controlled on the fly via the
;; `python-shell-font-lock-toggle' command.

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;; Pdb tracking: when you execute a block of code that contains some
;; call to pdb (or ipdb) it will prompt the block of code and will
;; follow the execution of pdb marking the current line with an arrow.

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;; Symbol completion: you can complete the symbol at point.  It uses
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;; the shell completion in background so you should run
;; `python-shell-send-buffer' from time to time to get better results.

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;; Skeletons: skeletons are provided for simple inserting of things like class,
;; def, for, import, if, try, and while.  These skeletons are
;; integrated with abbrev.  If you have `abbrev-mode' activated and
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;; `python-skeleton-autoinsert' is set to t, then whenever you type
;; the name of any of those defined and hit SPC, they will be
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;; automatically expanded.  As an alternative you can use the defined
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;; skeleton commands: `python-skeleton-<foo>'.
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;; FFAP: You can find the filename for a given module when using ffap
;; out of the box.  This feature needs an inferior python shell
;; running.

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;; Code check: Check the current file for errors with `python-check'
;; using the program defined in `python-check-command'.
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;; Eldoc: returns documentation for object at point by using the
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;; inferior python subprocess to inspect its documentation.  As you
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;; might guessed you should run `python-shell-send-buffer' from time
;; to time to get better results too.

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;; Imenu: There are two index building functions to be used as
;; `imenu-create-index-function': `python-imenu-create-index' (the
;; default one, builds the alist in form of a tree) and
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;; `python-imenu-create-flat-index'.  See also
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;; `python-imenu-format-item-label-function',
;; `python-imenu-format-parent-item-label-function',
;; `python-imenu-format-parent-item-jump-label-function' variables for
;; changing the way labels are formatted in the tree version.
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;; If you used python-mode.el you may miss auto-indentation when
;; inserting newlines.  To achieve the same behavior you have two
;; options:
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;; 1) Enable the minor-mode `electric-indent-mode' (enabled by
;;    default) and use RET.  If this mode is disabled use
;;    `newline-and-indent', bound to C-j.
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;; 2) Add the following hook in your .emacs:

;; (add-hook 'python-mode-hook
;;   #'(lambda ()
;;       (define-key python-mode-map "\C-m" 'newline-and-indent)))

;; I'd recommend the first one since you'll get the same behavior for
;; all modes out-of-the-box.

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;;; Installation:

;; Add this to your .emacs:

;; (add-to-list 'load-path "/folder/containing/file")
;; (require 'python)

;;; TODO:

;;; Code:

(require 'ansi-color)
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(require 'cl-lib)
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(require 'comint)
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(require 'json)
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(require 'tramp-sh)
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;; Avoid compiler warnings
(defvar view-return-to-alist)
(defvar compilation-error-regexp-alist)
(defvar outline-heading-end-regexp)
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(autoload 'comint-mode "comint")
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(autoload 'help-function-arglist "help-fns")
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;;;###autoload
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(add-to-list 'auto-mode-alist (cons (purecopy "\\.py[iw]?\\'") 'python-mode))
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;;;###autoload
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(add-to-list 'interpreter-mode-alist (cons (purecopy "python[0-9.]*") 'python-mode))
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(defgroup python nil
  "Python Language's flying circus support for Emacs."
  :group 'languages
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  :version "24.3"
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  :link '(emacs-commentary-link "python"))

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;;; 24.x Compat


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(eval-and-compile
  (unless (fboundp 'prog-first-column)
    (defun prog-first-column ()
      0))
  (unless (fboundp 'file-local-name)
    (defun file-local-name (file)
      "Return the local name component of FILE.
It returns a file name which can be used directly as argument of
`process-file', `start-file-process', or `shell-command'."
      (or (file-remote-p file 'localname) file))))

;; In Emacs 24.3 and earlier, `define-derived-mode' does not define
;; the hook variable, it only puts documentation on the symbol.
(defvar inferior-python-mode-hook)
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;;; Bindings

(defvar python-mode-map
  (let ((map (make-sparse-keymap)))
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    ;; Movement
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    (define-key map [remap backward-sentence] 'python-nav-backward-block)
    (define-key map [remap forward-sentence] 'python-nav-forward-block)
    (define-key map [remap backward-up-list] 'python-nav-backward-up-list)
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    (define-key map [remap mark-defun] 'python-mark-defun)
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    (define-key map "\C-c\C-j" 'imenu)
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    ;; Indent specific
    (define-key map "\177" 'python-indent-dedent-line-backspace)
    (define-key map (kbd "<backtab>") 'python-indent-dedent-line)
    (define-key map "\C-c<" 'python-indent-shift-left)
    (define-key map "\C-c>" 'python-indent-shift-right)
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    ;; Skeletons
    (define-key map "\C-c\C-tc" 'python-skeleton-class)
    (define-key map "\C-c\C-td" 'python-skeleton-def)
    (define-key map "\C-c\C-tf" 'python-skeleton-for)
    (define-key map "\C-c\C-ti" 'python-skeleton-if)
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    (define-key map "\C-c\C-tm" 'python-skeleton-import)
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    (define-key map "\C-c\C-tt" 'python-skeleton-try)
    (define-key map "\C-c\C-tw" 'python-skeleton-while)
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    ;; Shell interaction
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    (define-key map "\C-c\C-p" 'run-python)
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    (define-key map "\C-c\C-s" 'python-shell-send-string)
    (define-key map "\C-c\C-r" 'python-shell-send-region)
    (define-key map "\C-\M-x" 'python-shell-send-defun)
    (define-key map "\C-c\C-c" 'python-shell-send-buffer)
    (define-key map "\C-c\C-l" 'python-shell-send-file)
    (define-key map "\C-c\C-z" 'python-shell-switch-to-shell)
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    ;; Some util commands
    (define-key map "\C-c\C-v" 'python-check)
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    (define-key map "\C-c\C-f" 'python-eldoc-at-point)
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    (define-key map "\C-c\C-d" 'python-describe-at-point)
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    ;; Utilities
    (substitute-key-definition 'complete-symbol 'completion-at-point
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                               map global-map)
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    (easy-menu-define python-menu map "Python Mode menu"
      `("Python"
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        :help "Python-specific Features"
        ["Shift region left" python-indent-shift-left :active mark-active
         :help "Shift region left by a single indentation step"]
        ["Shift region right" python-indent-shift-right :active mark-active
         :help "Shift region right by a single indentation step"]
        "-"
        ["Start of def/class" beginning-of-defun
         :help "Go to start of outermost definition around point"]
        ["End of def/class" end-of-defun
         :help "Go to end of definition around point"]
        ["Mark def/class" mark-defun
         :help "Mark outermost definition around point"]
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        ["Jump to def/class" imenu
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         :help "Jump to a class or function definition"]
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        "--"
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        ("Skeletons")
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        "---"
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        ["Start interpreter" run-python
         :help "Run inferior Python process in a separate buffer"]
        ["Switch to shell" python-shell-switch-to-shell
         :help "Switch to running inferior Python process"]
        ["Eval string" python-shell-send-string
         :help "Eval string in inferior Python session"]
        ["Eval buffer" python-shell-send-buffer
         :help "Eval buffer in inferior Python session"]
        ["Eval region" python-shell-send-region
         :help "Eval region in inferior Python session"]
        ["Eval defun" python-shell-send-defun
         :help "Eval defun in inferior Python session"]
        ["Eval file" python-shell-send-file
         :help "Eval file in inferior Python session"]
        ["Debugger" pdb :help "Run pdb under GUD"]
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        "----"
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        ["Check file" python-check
         :help "Check file for errors"]
        ["Help on symbol" python-eldoc-at-point
         :help "Get help on symbol at point"]
        ["Complete symbol" completion-at-point
         :help "Complete symbol before point"]))
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    map)
  "Keymap for `python-mode'.")


;;; Python specialized rx

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(eval-and-compile
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  (defconst python-rx-constituents
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    `((block-start          . ,(rx symbol-start
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                                   (or "def" "class" "if" "elif" "else" "try"
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                                       "except" "finally" "for" "while" "with"
                                       ;; Python 3.5+ PEP492
                                       (and "async" (+ space)
                                            (or "def" "for" "with")))
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                                   symbol-end))
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      (dedenter            . ,(rx symbol-start
                                   (or "elif" "else" "except" "finally")
                                   symbol-end))
      (block-ender         . ,(rx symbol-start
                                  (or
                                   "break" "continue" "pass" "raise" "return")
                                  symbol-end))
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      (decorator            . ,(rx line-start (* space) ?@ (any letter ?_)
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                                   (* (any word ?_))))
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      (defun                . ,(rx symbol-start
                                   (or "def" "class"
                                       ;; Python 3.5+ PEP492
                                       (and "async" (+ space) "def"))
                                   symbol-end))
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      (if-name-main         . ,(rx line-start "if" (+ space) "__name__"
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                                   (+ space) "==" (+ space)
                                   (any ?' ?\") "__main__" (any ?' ?\")
                                   (* space) ?:))
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      (symbol-name          . ,(rx (any letter ?_) (* (any word ?_))))
      (open-paren           . ,(rx (or "{" "[" "(")))
      (close-paren          . ,(rx (or "}" "]" ")")))
      (simple-operator      . ,(rx (any ?+ ?- ?/ ?& ?^ ?~ ?| ?* ?< ?> ?= ?%)))
      ;; FIXME: rx should support (not simple-operator).
      (not-simple-operator  . ,(rx
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                                (not
                                 (any ?+ ?- ?/ ?& ?^ ?~ ?| ?* ?< ?> ?= ?%))))
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      ;; FIXME: Use regexp-opt.
      (operator             . ,(rx (or "+" "-" "/" "&" "^" "~" "|" "*" "<" ">"
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                                       "=" "%" "**" "//" "<<" ">>" "<=" "!="
                                       "==" ">=" "is" "not")))
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      ;; FIXME: Use regexp-opt.
      (assignment-operator  . ,(rx (or "=" "+=" "-=" "*=" "/=" "//=" "%=" "**="
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                                       ">>=" "<<=" "&=" "^=" "|=")))
      (string-delimiter . ,(rx (and
                                ;; Match even number of backslashes.
                                (or (not (any ?\\ ?\' ?\")) point
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                                    ;; Quotes might be preceded by an escaped quote.
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                                    (and (or (not (any ?\\)) point) ?\\
                                         (* ?\\ ?\\) (any ?\' ?\")))
                                (* ?\\ ?\\)
                                ;; Match single or triple quotes of any kind.
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                                (group (or  "\"" "\"\"\"" "'" "'''")))))
      (coding-cookie . ,(rx line-start ?# (* space)
                            (or
                             ;; # coding=<encoding name>
                             (: "coding" (or ?: ?=) (* space) (group-n 1 (+ (or word ?-))))
                             ;; # -*- coding: <encoding name> -*-
                             (: "-*-" (* space) "coding:" (* space)
                                (group-n 1 (+ (or word ?-))) (* space) "-*-")
                             ;; # vim: set fileencoding=<encoding name> :
                             (: "vim:" (* space) "set" (+ space)
                                "fileencoding" (* space) ?= (* space)
                                (group-n 1 (+ (or word ?-))) (* space) ":")))))
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    "Additional Python specific sexps for `python-rx'")

  (defmacro python-rx (&rest regexps)
    "Python mode specialized rx macro.
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This variant of `rx' supports common Python named REGEXPS."
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    (let ((rx-constituents (append python-rx-constituents rx-constituents)))
      (cond ((null regexps)
             (error "No regexp"))
            ((cdr regexps)
             (rx-to-string `(and ,@regexps) t))
            (t
             (rx-to-string (car regexps) t))))))
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;;; Font-lock and syntax
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(eval-and-compile
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  (defun python-syntax--context-compiler-macro (form type &optional syntax-ppss)
    (pcase type
      (`'comment
       `(let ((ppss (or ,syntax-ppss (syntax-ppss))))
          (and (nth 4 ppss) (nth 8 ppss))))
      (`'string
       `(let ((ppss (or ,syntax-ppss (syntax-ppss))))
          (and (nth 3 ppss) (nth 8 ppss))))
      (`'paren
       `(nth 1 (or ,syntax-ppss (syntax-ppss))))
      (_ form))))

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(defun python-syntax-context (type &optional syntax-ppss)
  "Return non-nil if point is on TYPE using SYNTAX-PPSS.
TYPE can be `comment', `string' or `paren'.  It returns the start
character address of the specified TYPE."
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  (declare (compiler-macro python-syntax--context-compiler-macro))
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  (let ((ppss (or syntax-ppss (syntax-ppss))))
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    (pcase type
      (`comment (and (nth 4 ppss) (nth 8 ppss)))
      (`string (and (nth 3 ppss) (nth 8 ppss)))
      (`paren (nth 1 ppss))
      (_ nil))))
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(defun python-syntax-context-type (&optional syntax-ppss)
  "Return the context type using SYNTAX-PPSS.
The type returned can be `comment', `string' or `paren'."
  (let ((ppss (or syntax-ppss (syntax-ppss))))
    (cond
     ((nth 8 ppss) (if (nth 4 ppss) 'comment 'string))
     ((nth 1 ppss) 'paren))))

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(defsubst python-syntax-comment-or-string-p (&optional ppss)
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  "Return non-nil if PPSS is inside comment or string."
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  (nth 8 (or ppss (syntax-ppss))))

(defsubst python-syntax-closing-paren-p ()
  "Return non-nil if char after point is a closing paren."
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  (eql (syntax-class (syntax-after (point)))
       (syntax-class (string-to-syntax ")"))))
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(define-obsolete-function-alias
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  'python-info-ppss-context #'python-syntax-context "24.3")
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(define-obsolete-function-alias
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  'python-info-ppss-context-type #'python-syntax-context-type "24.3")
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(define-obsolete-function-alias
  'python-info-ppss-comment-or-string-p
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  #'python-syntax-comment-or-string-p "24.3")
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(defun python-font-lock-syntactic-face-function (state)
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  "Return syntactic face given STATE."
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  (if (nth 3 state)
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      (if (python-info-docstring-p state)
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          font-lock-doc-face
        font-lock-string-face)
    font-lock-comment-face))

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(defvar python-font-lock-keywords
  ;; Keywords
  `(,(rx symbol-start
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         (or
          "and" "del" "from" "not" "while" "as" "elif" "global" "or" "with"
          "assert" "else" "if" "pass" "yield" "break" "except" "import" "class"
          "in" "raise" "continue" "finally" "is" "return" "def" "for" "lambda"
          "try"
          ;; Python 2:
          "print" "exec"
          ;; Python 3:
          ;; False, None, and True are listed as keywords on the Python 3
          ;; documentation, but since they also qualify as constants they are
          ;; fontified like that in order to keep font-lock consistent between
          ;; Python versions.
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          "nonlocal"
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          ;; Python 3.5+ PEP492
          (and "async" (+ space) (or "def" "for" "with"))
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          "await"
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          ;; Extra:
          "self")
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         symbol-end)
    ;; functions
    (,(rx symbol-start "def" (1+ space) (group (1+ (or word ?_))))
     (1 font-lock-function-name-face))
    ;; classes
    (,(rx symbol-start "class" (1+ space) (group (1+ (or word ?_))))
     (1 font-lock-type-face))
    ;; Constants
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    (,(rx symbol-start
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          (or
           "Ellipsis" "False" "None" "NotImplemented" "True" "__debug__"
           ;; copyright, license, credits, quit and exit are added by the site
           ;; module and they are not intended to be used in programs
           "copyright" "credits" "exit" "license" "quit")
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          symbol-end) . font-lock-constant-face)
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    ;; Decorators.
    (,(rx line-start (* (any " \t")) (group "@" (1+ (or word ?_))
                                            (0+ "." (1+ (or word ?_)))))
     (1 font-lock-type-face))
    ;; Builtin Exceptions
    (,(rx symbol-start
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          (or
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           ;; Python 2 and 3:
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           "ArithmeticError" "AssertionError" "AttributeError" "BaseException"
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           "BufferError" "BytesWarning" "DeprecationWarning" "EOFError"
           "EnvironmentError" "Exception" "FloatingPointError" "FutureWarning"
           "GeneratorExit" "IOError" "ImportError" "ImportWarning"
           "IndentationError" "IndexError" "KeyError" "KeyboardInterrupt"
           "LookupError" "MemoryError" "NameError" "NotImplementedError"
           "OSError" "OverflowError" "PendingDeprecationWarning"
           "ReferenceError" "RuntimeError" "RuntimeWarning" "StopIteration"
           "SyntaxError" "SyntaxWarning" "SystemError" "SystemExit" "TabError"
           "TypeError" "UnboundLocalError" "UnicodeDecodeError"
           "UnicodeEncodeError" "UnicodeError" "UnicodeTranslateError"
           "UnicodeWarning" "UserWarning" "ValueError" "Warning"
           "ZeroDivisionError"
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           ;; Python 2:
           "StandardError"
           ;; Python 3:
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           "BlockingIOError" "BrokenPipeError" "ChildProcessError"
           "ConnectionAbortedError" "ConnectionError" "ConnectionRefusedError"
           "ConnectionResetError" "FileExistsError" "FileNotFoundError"
           "InterruptedError" "IsADirectoryError" "NotADirectoryError"
           "PermissionError" "ProcessLookupError" "RecursionError"
           "ResourceWarning" "StopAsyncIteration" "TimeoutError"
           ;; OS specific
           "VMSError" "WindowsError"
           )
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          symbol-end) . font-lock-type-face)
    ;; Builtins
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    (,(rx symbol-start
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          (or
           "abs" "all" "any" "bin" "bool" "callable" "chr" "classmethod"
           "compile" "complex" "delattr" "dict" "dir" "divmod" "enumerate"
           "eval" "filter" "float" "format" "frozenset" "getattr" "globals"
           "hasattr" "hash" "help" "hex" "id" "input" "int" "isinstance"
           "issubclass" "iter" "len" "list" "locals" "map" "max" "memoryview"
           "min" "next" "object" "oct" "open" "ord" "pow" "print" "property"
           "range" "repr" "reversed" "round" "set" "setattr" "slice" "sorted"
           "staticmethod" "str" "sum" "super" "tuple" "type" "vars" "zip"
           "__import__"
           ;; Python 2:
           "basestring" "cmp" "execfile" "file" "long" "raw_input" "reduce"
           "reload" "unichr" "unicode" "xrange" "apply" "buffer" "coerce"
           "intern"
           ;; Python 3:
           "ascii" "bytearray" "bytes" "exec"
           ;; Extra:
           "__all__" "__doc__" "__name__" "__package__")
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          symbol-end) . font-lock-builtin-face)
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    ;; assignments
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    ;; support for a = b = c = 5
    (,(lambda (limit)
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        (let ((re (python-rx (group (+ (any word ?. ?_)))
                             (? ?\[ (+ (not (any  ?\]))) ?\]) (* space)
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                             assignment-operator))
              (res nil))
          (while (and (setq res (re-search-forward re limit t))
                      (or (python-syntax-context 'paren)
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                          (equal (char-after (point)) ?=))))
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          res))
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     (1 font-lock-variable-name-face nil nil))
    ;; support for a, b, c = (1, 2, 3)
    (,(lambda (limit)
        (let ((re (python-rx (group (+ (any word ?. ?_))) (* space)
                             (* ?, (* space) (+ (any word ?. ?_)) (* space))
                             ?, (* space) (+ (any word ?. ?_)) (* space)
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                             assignment-operator))
              (res nil))
          (while (and (setq res (re-search-forward re limit t))
                      (goto-char (match-end 1))
                      (python-syntax-context 'paren)))
          res))
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     (1 font-lock-variable-name-face nil nil))))

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(defconst python-syntax-propertize-function
  (syntax-propertize-rules
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   ((python-rx string-delimiter)
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    (0 (ignore (python-syntax-stringify))))))
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(defvar python-prettify-symbols-alist
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  '(("lambda"  . ?λ)
    ("and" . ?)
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    ("or" . ?))
  "Value for `prettify-symbols-alist' in `python-mode'.")

(define-obsolete-variable-alias 'python--prettify-symbols-alist
  'python-prettify-symbols-alist "26.1")
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(defsubst python-syntax-count-quotes (quote-char &optional point limit)
  "Count number of quotes around point (max is 3).
QUOTE-CHAR is the quote char to count.  Optional argument POINT is
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the point where scan starts (defaults to current point), and LIMIT
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is used to limit the scan."
  (let ((i 0))
    (while (and (< i 3)
                (or (not limit) (< (+ point i) limit))
                (eq (char-after (+ point i)) quote-char))
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      (setq i (1+ i)))
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    i))

(defun python-syntax-stringify ()
  "Put `syntax-table' property correctly on single/triple quotes."
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  (let* ((num-quotes (length (match-string-no-properties 1)))
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         (ppss (prog2
                   (backward-char num-quotes)
                   (syntax-ppss)
                 (forward-char num-quotes)))
         (string-start (and (not (nth 4 ppss)) (nth 8 ppss)))
         (quote-starting-pos (- (point) num-quotes))
         (quote-ending-pos (point))
         (num-closing-quotes
          (and string-start
               (python-syntax-count-quotes
                (char-before) string-start quote-starting-pos))))
    (cond ((and string-start (= num-closing-quotes 0))
           ;; This set of quotes doesn't match the string starting
           ;; kind. Do nothing.
           nil)
          ((not string-start)
           ;; This set of quotes delimit the start of a string.
           (put-text-property quote-starting-pos (1+ quote-starting-pos)
                              'syntax-table (string-to-syntax "|")))
          ((= num-quotes num-closing-quotes)
           ;; This set of quotes delimit the end of a string.
           (put-text-property (1- quote-ending-pos) quote-ending-pos
                              'syntax-table (string-to-syntax "|")))
          ((> num-quotes num-closing-quotes)
           ;; This may only happen whenever a triple quote is closing
           ;; a single quoted string. Add string delimiter syntax to
           ;; all three quotes.
           (put-text-property quote-starting-pos quote-ending-pos
                              'syntax-table (string-to-syntax "|"))))))
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(defvar python-mode-syntax-table
  (let ((table (make-syntax-table)))
    ;; Give punctuation syntax to ASCII that normally has symbol
    ;; syntax or has word syntax and isn't a letter.
    (let ((symbol (string-to-syntax "_"))
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          (sst (standard-syntax-table)))
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      (dotimes (i 128)
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        (unless (= i ?_)
          (if (equal symbol (aref sst i))
              (modify-syntax-entry i "." table)))))
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    (modify-syntax-entry ?$ "." table)
    (modify-syntax-entry ?% "." table)
    ;; exceptions
    (modify-syntax-entry ?# "<" table)
    (modify-syntax-entry ?\n ">" table)
    (modify-syntax-entry ?' "\"" table)
    (modify-syntax-entry ?` "$" table)
    table)
  "Syntax table for Python files.")

(defvar python-dotty-syntax-table
  (let ((table (make-syntax-table python-mode-syntax-table)))
    (modify-syntax-entry ?. "w" table)
    (modify-syntax-entry ?_ "w" table)
    table)
  "Dotty syntax table for Python files.
It makes underscores and dots word constituent chars.")


;;; Indentation

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(define-obsolete-variable-alias
  'python-indent 'python-indent-offset "24.3")

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(defcustom python-indent-offset 4
  "Default indentation offset for Python."
  :group 'python
  :type 'integer
  :safe 'integerp)

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(define-obsolete-variable-alias
  'python-guess-indent 'python-indent-guess-indent-offset "24.3")

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(defcustom python-indent-guess-indent-offset t
  "Non-nil tells Python mode to guess `python-indent-offset' value."
  :type 'boolean
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  :group 'python
  :safe 'booleanp)
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(defcustom python-indent-guess-indent-offset-verbose t
  "Non-nil means to emit a warning when indentation guessing fails."
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  :version "25.1"
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  :type 'boolean
  :group 'python
  :safe' booleanp)

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(defcustom python-indent-trigger-commands
  '(indent-for-tab-command yas-expand yas/expand)
  "Commands that might trigger a `python-indent-line' call."
  :type '(repeat symbol)
  :group 'python)

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(defcustom python-indent-def-block-scale 2
  "Multiplier applied to indentation inside multi-line def blocks."
  :version "26.1"
  :type 'integer
  :safe 'natnump)

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(defvar python-indent-current-level 0
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  "Deprecated var available for compatibility.")
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(defvar python-indent-levels '(0)
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  "Deprecated var available for compatibility.")

(make-obsolete-variable
 'python-indent-current-level
 "The indentation API changed to avoid global state.
The function `python-indent-calculate-levels' does not use it
anymore.  If you were defadvising it and or depended on this
variable for indentation customizations, refactor your code to
work on `python-indent-calculate-indentation' instead."
 "24.5")

(make-obsolete-variable
 'python-indent-levels
 "The indentation API changed to avoid global state.
The function `python-indent-calculate-levels' does not use it
anymore.  If you were defadvising it and or depended on this
variable for indentation customizations, refactor your code to
work on `python-indent-calculate-indentation' instead."
 "24.5")
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(defun python-indent-guess-indent-offset ()
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  "Guess and set `python-indent-offset' for the current buffer."
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  (interactive)
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  (save-excursion
    (save-restriction
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      (widen)
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      (goto-char (point-min))
      (let ((block-end))
        (while (and (not block-end)
                    (re-search-forward
                     (python-rx line-start block-start) nil t))
          (when (and
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                 (not (python-syntax-context-type))
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                 (progn
                   (goto-char (line-end-position))
                   (python-util-forward-comment -1)
                   (if (equal (char-before) ?:)
                       t
                     (forward-line 1)
                     (when (python-info-block-continuation-line-p)
                       (while (and (python-info-continuation-line-p)
                                   (not (eobp)))
                         (forward-line 1))
                       (python-util-forward-comment -1)
                       (when (equal (char-before) ?:)
                         t)))))
            (setq block-end (point-marker))))
        (let ((indentation
               (when block-end
                 (goto-char block-end)
                 (python-util-forward-comment)
                 (current-indentation))))
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          (if (and indentation (not (zerop indentation)))
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              (set (make-local-variable 'python-indent-offset) indentation)
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            (when python-indent-guess-indent-offset-verbose
              (message "Can't guess python-indent-offset, using defaults: %s"
                       python-indent-offset))))))))
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(defun python-indent-context ()
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  "Get information about the current indentation context.
Context is returned in a cons with the form (STATUS . START).

STATUS can be one of the following:

keyword
-------

:after-comment
 - Point is after a comment line.
 - START is the position of the \"#\" character.
:inside-string
 - Point is inside string.
 - START is the position of the first quote that starts it.
:no-indent
 - No possible indentation case matches.
 - START is always zero.

:inside-paren
 - Fallback case when point is inside paren.
 - START is the first non space char position *after* the open paren.
:inside-paren-at-closing-nested-paren
 - Point is on a line that contains a nested paren closer.
 - START is the position of the open paren it closes.
:inside-paren-at-closing-paren
 - Point is on a line that contains a paren closer.
 - START is the position of the open paren.
:inside-paren-newline-start
 - Point is inside a paren with items starting in their own line.
 - START is the position of the open paren.
:inside-paren-newline-start-from-block
 - Point is inside a paren with items starting in their own line
   from a block start.
 - START is the position of the open paren.

:after-backslash
 - Fallback case when point is after backslash.
 - START is the char after the position of the backslash.
:after-backslash-assignment-continuation
 - Point is after a backslashed assignment.
 - START is the char after the position of the backslash.
:after-backslash-block-continuation
 - Point is after a backslashed block continuation.
 - START is the char after the position of the backslash.
:after-backslash-dotted-continuation
 - Point is after a backslashed dotted continuation.  Previous
   line must contain a dot to align with.
 - START is the char after the position of the backslash.
:after-backslash-first-line
 - First line following a backslashed continuation.
 - START is the char after the position of the backslash.

:after-block-end
 - Point is after a line containing a block ender.
 - START is the position where the ender starts.
:after-block-start
 - Point is after a line starting a block.
 - START is the position where the block starts.
:after-line
 - Point is after a simple line.
 - START is the position where the previous line starts.
:at-dedenter-block-start
 - Point is on a line starting a dedenter block.
 - START is the position where the dedenter block starts."
    (let ((ppss (save-excursion
                  (beginning-of-line)
                  (syntax-ppss))))
      (cond
       ;; Beginning of buffer.
       ((= (line-number-at-pos) 1)
        (cons :no-indent 0))
       ;; Inside a string.
       ((let ((start (python-syntax-context 'string ppss)))
          (when start
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            (cons (if (python-info-docstring-p)
                      :inside-docstring
                    :inside-string) start))))
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       ;; Inside a paren.
       ((let* ((start (python-syntax-context 'paren ppss))
               (starts-in-newline
                (when start
                  (save-excursion
                    (goto-char start)
                    (forward-char)
                    (not
                     (= (line-number-at-pos)
                        (progn
                          (python-util-forward-comment)
                          (line-number-at-pos))))))))
          (when start
            (cond
             ;; Current line only holds the closing paren.
             ((save-excursion
                (skip-syntax-forward " ")
                (when (and (python-syntax-closing-paren-p)
                           (progn
                             (forward-char 1)
                             (not (python-syntax-context 'paren))))
                  (cons :inside-paren-at-closing-paren start))))
             ;; Current line only holds a closing paren for nested.
             ((save-excursion
                (back-to-indentation)
                (python-syntax-closing-paren-p))
              (cons :inside-paren-at-closing-nested-paren start))
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             ;; This line starts from an opening block in its own line.
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             ((save-excursion
                (goto-char start)
                (when (and
                       starts-in-newline
                       (save-excursion
                         (back-to-indentation)
                         (looking-at (python-rx block-start))))
                  (cons
                   :inside-paren-newline-start-from-block start))))
             (starts-in-newline
              (cons :inside-paren-newline-start start))
             ;; General case.
             (t (cons :inside-paren
                      (save-excursion
                        (goto-char (1+ start))
                        (skip-syntax-forward "(" 1)
                        (skip-syntax-forward " ")
                        (point))))))))
       ;; After backslash.
       ((let ((start (when (not (python-syntax-comment-or-string-p ppss))
                       (python-info-line-ends-backslash-p
                        (1- (line-number-at-pos))))))
          (when start
            (cond
             ;; Continuation of dotted expression.
             ((save-excursion
                (back-to-indentation)
                (when (eq (char-after) ?\.)
                  ;; Move point back until it's not inside a paren.
                  (while (prog2
                             (forward-line -1)
                             (and (not (bobp))
                                  (python-syntax-context 'paren))))
                  (goto-char (line-end-position))
                  (while (and (search-backward
                               "." (line-beginning-position) t)
                              (python-syntax-context-type)))
                  ;; Ensure previous statement has dot to align with.
                  (when (and (eq (char-after) ?\.)
                             (not (python-syntax-context-type)))
                    (cons :after-backslash-dotted-continuation (point))))))
             ;; Continuation of block definition.
             ((let ((block-continuation-start
                     (python-info-block-continuation-line-p)))
                (when block-continuation-start
                  (save-excursion
                    (goto-char block-continuation-start)
                    (re-search-forward
                     (python-rx block-start (* space))
                     (line-end-position) t)
                    (cons :after-backslash-block-continuation (point))))))
             ;; Continuation of assignment.
             ((let ((assignment-continuation-start
                     (python-info-assignment-continuation-line-p)))
                (when assignment-continuation-start
                  (save-excursion
                    (goto-char assignment-continuation-start)
                    (cons :after-backslash-assignment-continuation (point))))))
             ;; First line after backslash continuation start.
             ((save-excursion
                (goto-char start)
                (when (or (= (line-number-at-pos) 1)
                          (not (python-info-beginning-of-backslash
                                (1- (line-number-at-pos)))))
                  (cons :after-backslash-first-line start))))
             ;; General case.
             (t (cons :after-backslash start))))))
       ;; After beginning of block.
       ((let ((start (save-excursion
                       (back-to-indentation)
                       (python-util-forward-comment -1)
                       (when (equal (char-before) ?:)
                         (python-nav-beginning-of-block)))))
          (when start
            (cons :after-block-start start))))
       ;; At dedenter statement.
       ((let ((start (python-info-dedenter-statement-p)))
          (when start
            (cons :at-dedenter-block-start start))))
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       ;; After normal line, comment or ender (default case).
       ((save-excursion
          (back-to-indentation)
          (skip-chars-backward " \t\n")
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          (if (bobp)
              (cons :no-indent 0)
            (python-nav-beginning-of-statement)
            (cons
             (cond ((python-info-current-line-comment-p)
                    :after-comment)
                   ((save-excursion
                      (goto-char (line-end-position))
                      (python-util-forward-comment -1)
                      (python-nav-beginning-of-statement)
                      (looking-at (python-rx block-ender)))
                    :after-block-end)
                   (t :after-line))
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             (point))))))))
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(defun python-indent--calculate-indentation ()
  "Internal implementation of `python-indent-calculate-indentation'.
May return an integer for the maximum possible indentation at
current context or a list of integers.  The latter case is only
happening for :at-dedenter-block-start context since the
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possibilities can be narrowed to specific indentation points."
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    (save-excursion
      (pcase (python-indent-context)
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        (`(:no-indent . ,_) (prog-first-column)) ; usually 0
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        (`(,(or :after-line
                :after-comment
                :inside-string
                :after-backslash
                :inside-paren-at-closing-paren
                :inside-paren-at-closing-nested-paren) . ,start)
         ;; Copy previous indentation.
         (goto-char start)
         (current-indentation))
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        (`(:inside-docstring . ,start)
         (let* ((line-indentation (current-indentation))
                (base-indent (progn
                               (goto-char start)
                               (current-indentation))))
           (max line-indentation base-indent)))
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        (`(,(or :after-block-start
                :after-backslash-first-line
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                :after-backslash-assignment-continuation
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                :inside-paren-newline-start) . ,start)
         ;; Add one indentation level.
         (goto-char start)
         (+ (current-indentation) python-indent-offset))
        (`(,(or :inside-paren
                :after-backslash-block-continuation
                :after-backslash-dotted-continuation) . ,start)
         ;; Use the column given by the context.
         (goto-char start)
         (current-column))
        (`(:after-block-end . ,start)
         ;; Subtract one indentation level.
         (goto-char start)
         (- (current-indentation) python-indent-offset))
        (`(:at-dedenter-block-start . ,_)
         ;; List all possible indentation levels from opening blocks.
         (let ((opening-block-start-points
                (python-info-dedenter-opening-block-positions)))
           (if (not opening-block-start-points)
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               (prog-first-column) ; if not found default to first column
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             (mapcar (lambda (pos)
                       (save-excursion
                         (goto-char pos)
                         (current-indentation)))
                     opening-block-start-points))))
        (`(,(or :inside-paren-newline-start-from-block) . ,start)
         (goto-char start)
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         (+ (current-indentation)
            (* python-indent-offset python-indent-def-block-scale))))))
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(defun python-indent--calculate-levels (indentation)
  "Calculate levels list given INDENTATION.
Argument INDENTATION can either be an integer or a list of
integers.  Levels are returned in ascending order, and in the
case INDENTATION is a list, this order is enforced."
  (if (listp indentation)
      (sort (copy-sequence indentation) #'<)
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    (nconc (number-sequence (prog-first-column) (1- indentation)
                            python-indent-offset)
           (list indentation))))
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(defun python-indent--previous-level (levels indentation)
  "Return previous level from LEVELS relative to INDENTATION."
  (let* ((levels (sort (copy-sequence levels) #'>))
         (default (car levels)))
    (catch 'return
      (dolist (level levels)
        (when (funcall #'< level indentation)
          (throw 'return level)))
      default)))

(defun python-indent-calculate-indentation (&optional previous)
  "Calculate indentation.
Get indentation of PREVIOUS level when argument is non-nil.
Return the max level of the cycle when indentation reaches the
minimum."
  (let* ((indentation (python-indent--calculate-indentation))
         (levels (python-indent--calculate-levels indentation)))
    (if previous
        (python-indent--previous-level levels (current-indentation))
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      (if levels
          (apply #'max levels)
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        (prog-first-column)))))
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(defun python-indent-line (&optional previous)
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  "Internal implementation of `python-indent-line-function'.
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Use the PREVIOUS level when argument is non-nil, otherwise indent
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to the maximum available level.  When indentation is the minimum
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possible and PREVIOUS is non-nil, cycle back to the maximum
level."
  (let ((follow-indentation-p
         ;; Check if point is within indentation.
         (and (<= (line-beginning-position) (point))
              (>= (+ (line-beginning-position)
                     (current-indentation))
                  (point)))))
    (save-excursion
      (indent-line-to
       (python-indent-calculate-indentation previous))
      (python-info-dedenter-opening-block-message))
    (when follow-indentation-p
      (back-to-indentation))))
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(defun python-indent-calculate-levels ()
  "Return possible indentation levels."
  (python-indent--calculate-levels
   (python-indent--calculate-indentation)))
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(defun python-indent-line-function ()
  "`indent-line-function' for Python mode.
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When the variable `last-command' is equal to one of the symbols
inside `python-indent-trigger-commands' it cycles possible
indentation levels from right to left."
  (python-indent-line
   (and (memq this-command python-indent-trigger-commands)
        (eq last-command this-command))))
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(defun python-indent-dedent-line ()
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  "De-indent current line."
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  (interactive "*")
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  (when (and (not (bolp))
           (not (python-syntax-comment-or-string-p))
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           (= (current-indentation) (current-column)))
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      (python-indent-line t)
      t))
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(defun python-indent-dedent-line-backspace (arg)
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  "De-indent current line.
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Argument ARG is passed to `backward-delete-char-untabify' when
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point is not in between the indentation."
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  (interactive "*p")
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  (unless (python-indent-dedent-line)
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    (backward-delete-char-untabify arg)))
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(put 'python-indent-dedent-line-backspace 'delete-selection 'supersede)
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(defun python-indent-region (start end)
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  "Indent a Python region automagically.
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Called from a program, START and END specify the region to indent."
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  (let ((deactivate-mark nil))
    (save-excursion
      (goto-char end)
      (setq end (point-marker))
      (goto-char start)
      (or (bolp) (forward-line 1))
      (while (< (point) end)
        (or (and (bolp) (eolp))
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            (when (and
                   ;; Skip if previous line is empty or a comment.
                   (save-excursion
                     (let ((line-is-comment-p
                            (python-info-current-line-comment-p)))
                       (forward-line -1)
                       (not
                        (or (and (python-info-current-line-comment-p)
                                 ;; Unless this line is a comment too.
                                 (not line-is-comment-p))
                            (python-info-current-line-empty-p)))))
                   ;; Don't mess with strings, unless it's the
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                   ;; enclosing set of quotes or a docstring.
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                   (or (not (python-syntax-context 'string))
                       (eq
                        (syntax-after
                         (+ (1- (point))
                            (current-indentation)
                            (python-syntax-count-quotes (char-after) (point))))
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                        (string-to-syntax "|"))
                       (python-info-docstring-p))