Merge pull request matplotlib#14016 from anntzer/backend-pep8

pep8ify backends.

Author: efiring

.flake8

@@ -35,11 +35,6 @@ per-file-ignores =
 
     lib/matplotlib/_cm.py: E202, E203, E302
     lib/matplotlib/_mathtext_data.py: E203, E261
-    lib/matplotlib/backends/_backend_tk.py: E501
-    lib/matplotlib/backends/backend_agg.py: E302
-    lib/matplotlib/backends/backend_cairo.py: E203, E221, E402
-    lib/matplotlib/backends/backend_gtk3.py: E203, E221, E225, E251, E501
-    lib/matplotlib/backends/qt_editor/_formlayout.py: E501
     lib/matplotlib/font_manager.py: E203, E221, E251, E501
     lib/matplotlib/fontconfig_pattern.py: E201, E203, E221, E222, E225
     lib/matplotlib/mathtext.py: E201, E202, E203, E211, E221, E222, E225, E251, E301, E402

doc/api/next_api_changes/2019-04-21-AL.rst

@@ -0,0 +1,14 @@
+Removals
+````````
+
+The following API elements have been removed:
+
+- ``backend_gtk3.PIXELS_PER_INCH``,
+- ``backend_pgf.re_escapetext``, ``backend_pgf.re_mathdefault``.
+
+Deprecations
+````````````
+
+The following API elements are deprecated:
+
+- ``backend_pgf.repl_escapetext``, ``backend_pgf.repl_mathdefault``.

lib/matplotlib/backends/_backend_tk.py

@@ -11,7 +11,7 @@
 import numpy as np
 
 import matplotlib
-from matplotlib import backend_tools, rcParams, cbook
+from matplotlib import backend_tools, cbook, rcParams
 from matplotlib.backend_bases import (
     _Backend, FigureCanvasBase, FigureManagerBase, NavigationToolbar2,
     StatusbarBase, TimerBase, ToolContainerBase, cursors)
@@ -42,10 +42,6 @@ def _restore_foreground_window_at_end():
 
 backend_version = tk.TkVersion
 
-# the true dots per inch on the screen; should be display dependent
-# see http://groups.google.com/groups?q=screen+dpi+x11&hl=en&lr=&ie=UTF-8&oe=UTF-8&safe=off&selm=7077.26e81ad5%40swift.cs.tcd.ie&rnum=5 for some info about screen dpi
-PIXELS_PER_INCH = 75
-
 cursord = {
     cursors.MOVE: "fleur",
     cursors.HAND: "hand2",
@@ -208,11 +204,13 @@ def __init__(self, figure, master=None, resize_callback=None):
         self._tkcanvas.bind("<Enter>", self.enter_notify_event)
         self._tkcanvas.bind("<Leave>", self.leave_notify_event)
         self._tkcanvas.bind("<KeyRelease>", self.key_release)
-        for name in "<Button-1>", "<Button-2>", "<Button-3>":
+        for name in ["<Button-1>", "<Button-2>", "<Button-3>"]:
             self._tkcanvas.bind(name, self.button_press_event)
-        for name in "<Double-Button-1>", "<Double-Button-2>", "<Double-Button-3>":
+        for name in [
+                "<Double-Button-1>", "<Double-Button-2>", "<Double-Button-3>"]:
             self._tkcanvas.bind(name, self.button_dblclick_event)
-        for name in "<ButtonRelease-1>", "<ButtonRelease-2>", "<ButtonRelease-3>":
+        for name in [
+                "<ButtonRelease-1>", "<ButtonRelease-2>", "<ButtonRelease-3>"]:
             self._tkcanvas.bind(name, self.button_release_event)
 
         # Mouse wheel on Linux generates button 4/5 events

lib/matplotlib/backends/backend_agg.py

@@ -51,6 +51,7 @@
 
 backend_version = 'v2.2'
 
+
 def get_hinting_flag():
     mapping = {
         True: LOAD_FORCE_AUTOHINT,

lib/matplotlib/backends/backend_cairo.py

@@ -23,8 +23,6 @@
             "cairo backend requires that pycairo>=1.11.0 or cairocffi"
             "is installed")
 
-backend_version = cairo.version
-
 from .. import cbook
 from matplotlib.backend_bases import (
     _Backend, FigureCanvasBase, FigureManagerBase, GraphicsContextBase,
@@ -35,6 +33,9 @@
 from matplotlib.transforms import Affine2D
 
 
+backend_version = cairo.version
+
+
 if cairo.__name__ == "cairocffi":
     # Convert a pycairo context to a cairocffi one.
     def _to_context(ctx):
@@ -71,31 +72,31 @@ def _append_path(ctx, path, transform, clip=None):
 
 class RendererCairo(RendererBase):
     fontweights = {
-        100          : cairo.FONT_WEIGHT_NORMAL,
-        200          : cairo.FONT_WEIGHT_NORMAL,
-        300          : cairo.FONT_WEIGHT_NORMAL,
-        400          : cairo.FONT_WEIGHT_NORMAL,
-        500          : cairo.FONT_WEIGHT_NORMAL,
-        600          : cairo.FONT_WEIGHT_BOLD,
-        700          : cairo.FONT_WEIGHT_BOLD,
-        800          : cairo.FONT_WEIGHT_BOLD,
-        900          : cairo.FONT_WEIGHT_BOLD,
-        'ultralight' : cairo.FONT_WEIGHT_NORMAL,
-        'light'      : cairo.FONT_WEIGHT_NORMAL,
-        'normal'     : cairo.FONT_WEIGHT_NORMAL,
-        'medium'     : cairo.FONT_WEIGHT_NORMAL,
-        'regular'    : cairo.FONT_WEIGHT_NORMAL,
-        'semibold'   : cairo.FONT_WEIGHT_BOLD,
-        'bold'       : cairo.FONT_WEIGHT_BOLD,
-        'heavy'      : cairo.FONT_WEIGHT_BOLD,
-        'ultrabold'  : cairo.FONT_WEIGHT_BOLD,
-        'black'      : cairo.FONT_WEIGHT_BOLD,
-                   }
+        100:          cairo.FONT_WEIGHT_NORMAL,
+        200:          cairo.FONT_WEIGHT_NORMAL,
+        300:          cairo.FONT_WEIGHT_NORMAL,
+        400:          cairo.FONT_WEIGHT_NORMAL,
+        500:          cairo.FONT_WEIGHT_NORMAL,
+        600:          cairo.FONT_WEIGHT_BOLD,
+        700:          cairo.FONT_WEIGHT_BOLD,
+        800:          cairo.FONT_WEIGHT_BOLD,
+        900:          cairo.FONT_WEIGHT_BOLD,
+        'ultralight': cairo.FONT_WEIGHT_NORMAL,
+        'light':      cairo.FONT_WEIGHT_NORMAL,
+        'normal':     cairo.FONT_WEIGHT_NORMAL,
+        'medium':     cairo.FONT_WEIGHT_NORMAL,
+        'regular':    cairo.FONT_WEIGHT_NORMAL,
+        'semibold':   cairo.FONT_WEIGHT_BOLD,
+        'bold':       cairo.FONT_WEIGHT_BOLD,
+        'heavy':      cairo.FONT_WEIGHT_BOLD,
+        'ultrabold':  cairo.FONT_WEIGHT_BOLD,
+        'black':      cairo.FONT_WEIGHT_BOLD,
+    }
     fontangles = {
-        'italic'  : cairo.FONT_SLANT_ITALIC,
-        'normal'  : cairo.FONT_SLANT_NORMAL,
-        'oblique' : cairo.FONT_SLANT_OBLIQUE,
-        }
+        'italic':  cairo.FONT_SLANT_ITALIC,
+        'normal':  cairo.FONT_SLANT_NORMAL,
+        'oblique': cairo.FONT_SLANT_OBLIQUE,
+    }
 
     def __init__(self, dpi):
         self.dpi = dpi
@@ -113,7 +114,7 @@ def set_ctx_from_surface(self, surface):
         # for PDF/PS/SVG surfaces, which have no way to report their extents.
 
     def set_width_height(self, width, height):
-        self.width  = width
+        self.width = width
         self.height = height
 
     def _fill_and_stroke(self, ctx, fill_c, alpha, alpha_overrides):
@@ -305,16 +306,16 @@ def points_to_pixels(self, points):
 
 class GraphicsContextCairo(GraphicsContextBase):
     _joind = {
-        'bevel' : cairo.LINE_JOIN_BEVEL,
-        'miter' : cairo.LINE_JOIN_MITER,
-        'round' : cairo.LINE_JOIN_ROUND,
-        }
+        'bevel':  cairo.LINE_JOIN_BEVEL,
+        'miter':  cairo.LINE_JOIN_MITER,
+        'round':  cairo.LINE_JOIN_ROUND,
+    }
 
     _capd = {
-        'butt'       : cairo.LINE_CAP_BUTT,
-        'projecting' : cairo.LINE_CAP_SQUARE,
-        'round'      : cairo.LINE_CAP_ROUND,
-        }
+        'butt':        cairo.LINE_CAP_BUTT,
+        'projecting':  cairo.LINE_CAP_SQUARE,
+        'round':       cairo.LINE_CAP_ROUND,
+    }
 
     def __init__(self, renderer):
         GraphicsContextBase.__init__(self)

lib/matplotlib/backends/backend_gtk3.py

@@ -36,17 +36,13 @@
 backend_version = "%s.%s.%s" % (
     Gtk.get_major_version(), Gtk.get_micro_version(), Gtk.get_minor_version())
 
-# the true dots per inch on the screen; should be display dependent
-# see http://groups.google.com/groups?q=screen+dpi+x11&hl=en&lr=&ie=UTF-8&oe=UTF-8&safe=off&selm=7077.26e81ad5%40swift.cs.tcd.ie&rnum=5 for some info about screen dpi
-PIXELS_PER_INCH = 96
-
 try:
     cursord = {
-        cursors.MOVE          : Gdk.Cursor.new(Gdk.CursorType.FLEUR),
-        cursors.HAND          : Gdk.Cursor.new(Gdk.CursorType.HAND2),
-        cursors.POINTER       : Gdk.Cursor.new(Gdk.CursorType.LEFT_PTR),
-        cursors.SELECT_REGION : Gdk.Cursor.new(Gdk.CursorType.TCROSS),
-        cursors.WAIT          : Gdk.Cursor.new(Gdk.CursorType.WATCH),
+        cursors.MOVE:          Gdk.Cursor.new(Gdk.CursorType.FLEUR),
+        cursors.HAND:          Gdk.Cursor.new(Gdk.CursorType.HAND2),
+        cursors.POINTER:       Gdk.Cursor.new(Gdk.CursorType.LEFT_PTR),
+        cursors.SELECT_REGION: Gdk.Cursor.new(Gdk.CursorType.TCROSS),
+        cursors.WAIT:          Gdk.Cursor.new(Gdk.CursorType.WATCH),
     }
 except TypeError as exc:
     # Happens when running headless.  Convert to ImportError to cooperate with
@@ -154,23 +150,23 @@ class FigureCanvasGTK3(Gtk.DrawingArea, FigureCanvasBase):
 
     # Setting this as a static constant prevents
     # this resulting expression from leaking
-    event_mask = (Gdk.EventMask.BUTTON_PRESS_MASK   |
-                  Gdk.EventMask.BUTTON_RELEASE_MASK |
-                  Gdk.EventMask.EXPOSURE_MASK       |
-                  Gdk.EventMask.KEY_PRESS_MASK      |
-                  Gdk.EventMask.KEY_RELEASE_MASK    |
-                  Gdk.EventMask.ENTER_NOTIFY_MASK   |
-                  Gdk.EventMask.LEAVE_NOTIFY_MASK   |
-                  Gdk.EventMask.POINTER_MOTION_MASK |
-                  Gdk.EventMask.POINTER_MOTION_HINT_MASK|
-                  Gdk.EventMask.SCROLL_MASK)
+    event_mask = (Gdk.EventMask.BUTTON_PRESS_MASK
+                  | Gdk.EventMask.BUTTON_RELEASE_MASK
+                  | Gdk.EventMask.EXPOSURE_MASK
+                  | Gdk.EventMask.KEY_PRESS_MASK
+                  | Gdk.EventMask.KEY_RELEASE_MASK
+                  | Gdk.EventMask.ENTER_NOTIFY_MASK
+                  | Gdk.EventMask.LEAVE_NOTIFY_MASK
+                  | Gdk.EventMask.POINTER_MOTION_MASK
+                  | Gdk.EventMask.POINTER_MOTION_HINT_MASK
+                  | Gdk.EventMask.SCROLL_MASK)
 
     def __init__(self, figure):
         FigureCanvasBase.__init__(self, figure)
         GObject.GObject.__init__(self)
 
-        self._idle_draw_id  = 0
-        self._lastCursor    = None
+        self._idle_draw_id = 0
+        self._lastCursor = None
 
         self.connect('scroll_event',         self.scroll_event)
         self.connect('button_press_event',   self.button_press_event)
@@ -200,25 +196,24 @@ def scroll_event(self, widget, event):
         x = event.x
         # flipy so y=0 is bottom of canvas
         y = self.get_allocation().height - event.y
-        if event.direction==Gdk.ScrollDirection.UP:
-            step = 1
-        else:
-            step = -1
+        step = 1 if event.direction == Gdk.ScrollDirection.UP else -1
         FigureCanvasBase.scroll_event(self, x, y, step, guiEvent=event)
         return False  # finish event propagation?
 
     def button_press_event(self, widget, event):
         x = event.x
         # flipy so y=0 is bottom of canvas
         y = self.get_allocation().height - event.y
-        FigureCanvasBase.button_press_event(self, x, y, event.button, guiEvent=event)
+        FigureCanvasBase.button_press_event(
+            self, x, y, event.button, guiEvent=event)
         return False  # finish event propagation?
 
     def button_release_event(self, widget, event):
         x = event.x
         # flipy so y=0 is bottom of canvas
         y = self.get_allocation().height - event.y
-        FigureCanvasBase.button_release_event(self, x, y, event.button, guiEvent=event)
+        FigureCanvasBase.button_release_event(
+            self, x, y, event.button, guiEvent=event)
         return False  # finish event propagation?
 
     def key_press_event(self, widget, event):
@@ -472,7 +467,8 @@ def set_cursor(self, cursor):
         Gtk.main_iteration()
 
     def draw_rubberband(self, event, x0, y0, x1, y1):
-        'adapted from http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/189744'
+        # adapted from
+        # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/189744
         self.ctx = self.canvas.get_property("window").cairo_create()
 
         # todo: instead of redrawing the entire figure, copy the part of
@@ -622,14 +618,14 @@ class FileChooserDialog(Gtk.FileChooserDialog):
     selected and presents the user with a menu of supported image formats
     """
     def __init__(self,
-                 title   = 'Save file',
-                 parent  = None,
-                 action  = Gtk.FileChooserAction.SAVE,
-                 buttons = (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
-                            Gtk.STOCK_SAVE,   Gtk.ResponseType.OK),
-                 path    = None,
-                 filetypes = [],
-                 default_filetype = None,
+                 title='Save file',
+                 parent=None,
+                 action=Gtk.FileChooserAction.SAVE,
+                 buttons=(Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
+                          Gtk.STOCK_SAVE, Gtk.ResponseType.OK),
+                 path=None,
+                 filetypes=[],
+                 default_filetype=None,
                  ):
         super().__init__(title, parent, action, buttons)
         self.set_default_response(Gtk.ResponseType.OK)
@@ -961,15 +957,11 @@ def error_msg_gtk(msg, parent=None):
         parent = parent.get_toplevel()
         if not parent.is_toplevel():
             parent = None
-
     if not isinstance(msg, str):
         msg = ','.join(map(str, msg))
-
     dialog = Gtk.MessageDialog(
-        parent         = parent,
-        type           = Gtk.MessageType.ERROR,
-        buttons        = Gtk.ButtonsType.OK,
-        message_format = msg)
+        parent=parent, type=Gtk.MessageType.ERROR, buttons=Gtk.ButtonsType.OK,
+        message_format=msg)
     dialog.run()
     dialog.destroy()
 

lib/matplotlib/backends/backend_pgf.py

@@ -68,39 +68,45 @@ def get_preamble():
 
 NO_ESCAPE = r"(?<!\\)(?:\\\\)*"
 re_mathsep = re.compile(NO_ESCAPE + r"\$")
-re_escapetext = re.compile(NO_ESCAPE + "([_^$%])")
-re_mathdefault = re.compile(NO_ESCAPE + r"(\\mathdefault)")
 
 
+@cbook.deprecated("3.2")
 def repl_escapetext(m):
     return "\\" + m.group(1)
 
 
+@cbook.deprecated("3.2")
 def repl_mathdefault(m):
     return m.group(0)[:-len(m.group(1))]
 
 
+_replace_escapetext = functools.partial(
+    # When the next character is _, ^, $, or % (not preceded by an escape),
+    # insert a backslash.
+    re.compile(NO_ESCAPE + "(?=[_^$%])").sub, "\\\\")
+_replace_mathdefault = functools.partial(
+    # Replace \mathdefault (when not preceded by an escape) by empty string.
+    re.compile(NO_ESCAPE + r"(\\mathdefault)").sub, "")
+
+
 def common_texification(text):
     """
     Do some necessary and/or useful substitutions for texts to be included in
     LaTeX documents.
     """
-
     # Sometimes, matplotlib adds the unknown command \mathdefault.
     # Not using \mathnormal instead since this looks odd for the latex cm font.
-    text = re_mathdefault.sub(repl_mathdefault, text)
-
+    text = _replace_mathdefault(text)
     # split text into normaltext and inline math parts
     parts = re_mathsep.split(text)
     for i, s in enumerate(parts):
         if not i % 2:
             # textmode replacements
-            s = re_escapetext.sub(repl_escapetext, s)
+            s = _replace_escapetext(s)
         else:
             # mathmode replacements
             s = r"\(\displaystyle %s\)" % s
         parts[i] = s
-
     return "".join(parts)