Merge pull request matplotlib#14205 from anntzer/e731

Obey flake8 "don't assign a lambda, use a def".

Author: dstansby

.flake8

@@ -41,7 +41,6 @@ per-file-ignores =
     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/backend_pgf.py: E731
     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
@@ -52,7 +51,6 @@ per-file-ignores =
     lib/matplotlib/tests/test_mathtext.py: E501
     lib/matplotlib/transforms.py: E201, E202, E203, E501
     lib/matplotlib/tri/triinterpolate.py: E201, E221
-    lib/matplotlib/type1font.py: E731
 
     lib/mpl_toolkits/axes_grid1/axes_divider.py: E402, E501
     lib/mpl_toolkits/axes_grid1/axes_size.py: E272

lib/matplotlib/backends/backend_pgf.py

@@ -77,9 +77,15 @@ def get_preamble():
 NO_ESCAPE = r"(?<!\\)(?:\\\\)*"
 re_mathsep = re.compile(NO_ESCAPE + r"\$")
 re_escapetext = re.compile(NO_ESCAPE + "([_^$%])")
-repl_escapetext = lambda m: "\\" + m.group(1)
 re_mathdefault = re.compile(NO_ESCAPE + r"(\\mathdefault)")
-repl_mathdefault = lambda m: m.group(0)[:-len(m.group(1))]
+
+
+def repl_escapetext(m):
+    return "\\" + m.group(1)
+
+
+def repl_mathdefault(m):
+    return m.group(0)[:-len(m.group(1))]
 
 
 def common_texification(text):
@@ -398,10 +404,9 @@ def __init__(self, figure, fh, dummy=False):
 
         if dummy:
             # dummy==True deactivate all methods
-            nop = lambda *args, **kwargs: None
             for m in RendererPgf.__dict__:
                 if m.startswith("draw_"):
-                    self.__dict__[m] = nop
+                    self.__dict__[m] = lambda *args, **kwargs: None
         else:
             # if fh does not belong to a filename, deactivate draw_image
             if not hasattr(fh, 'name') or not os.path.exists(fh.name):

lib/matplotlib/type1font.py

@@ -202,7 +202,7 @@ def _parse(self):
         # The spec calls this an ASCII format; in Python 2.x we could
         # just treat the strings and names as opaque bytes but let's
         # turn them into proper Unicode, and be lenient in case of high bytes.
-        convert = lambda x: x.decode('ascii', 'replace')
+        def convert(x): return x.decode('ascii', 'replace')
         for token, value in filtered:
             if token is _TokenType.name and value.startswith(b'/'):
                 key = convert(value[1:])