sys.platform is normalized to "linux" on Py3.

anntzer · anntzer · commit 3cae753b824c · 2018-03-07T19:48:46.000-08:00
... so we can just do an equality check. (Likewise, for Windows, sys.platform is *always* "win32".) (https://docs.python.org/3/library/sys.html#sys.platform)
diff --git a/lib/matplotlib/backends/_backend_tk.py b/lib/matplotlib/backends/_backend_tk.py
@@ -336,11 +336,10 @@ def button_press_event(self, event, dblclick=False):
         y = self.figure.bbox.height - event.y
         num = getattr(event, 'num', None)
 
-        if sys.platform=='darwin':
-            # 2 and 3 were reversed on the OSX platform I
-            # tested under tkagg
-            if   num==2: num=3
-            elif num==3: num=2
+        if sys.platform == 'darwin':
+            # 2 and 3 were reversed on the OSX platform I tested under tkagg.
+            if num == 2: num = 3
+            elif num == 3: num = 2
 
         FigureCanvasBase.button_press_event(self, x, y, num, dblclick=dblclick, guiEvent=event)
 
@@ -354,11 +353,10 @@ def button_release_event(self, event):
 
         num = getattr(event, 'num', None)
 
-        if sys.platform=='darwin':
-            # 2 and 3 were reversed on the OSX platform I
-            # tested under tkagg
-            if   num==2: num=3
-            elif num==3: num=2
+        if sys.platform == 'darwin':
+            # 2 and 3 were reversed on the OSX platform I tested under tkagg.
+            if num == 2: num = 3
+            elif num == 3: num = 2
 
         FigureCanvasBase.button_release_event(self, x, y, num, guiEvent=event)
 
@@ -387,8 +385,8 @@ def _get_key(self, event):
         val = event.keysym_num
         if val in self.keyvald:
             key = self.keyvald[val]
-        elif val == 0 and sys.platform == 'darwin' and \
-                                        event.keycode in self._keycode_lookup:
+        elif (val == 0 and sys.platform == 'darwin'
+              and event.keycode in self._keycode_lookup):
             key = self._keycode_lookup[event.keycode]
         elif val < 256:
             key = chr(val)
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -30,7 +30,7 @@
 
 # create a list of system fonts, all of these should work with xe/lua-latex
 system_fonts = []
-if sys.platform.startswith('win'):
+if sys.platform == 'win32':
     from matplotlib import font_manager
     for f in font_manager.win32InstalledFonts():
         try:
diff --git a/lib/matplotlib/cbook/__init__.py b/lib/matplotlib/cbook/__init__.py
@@ -829,34 +829,34 @@ def report_memory(i=0):  # argument may go away
     pid = os.getpid()
     if sys.platform == 'sunos5':
         try:
-            a2 = Popen(str('ps -p %d -o osz') % pid, shell=True,
+            a2 = Popen('ps -p %d -o osz' % pid, shell=True,
                        stdout=PIPE).stdout.readlines()
         except OSError:
             raise NotImplementedError(
                 "report_memory works on Sun OS only if "
                 "the 'ps' program is found")
         mem = int(a2[-1].strip())
-    elif sys.platform.startswith('linux'):
+    elif sys.platform == 'linux':
         try:
-            a2 = Popen(str('ps -p %d -o rss,sz') % pid, shell=True,
+            a2 = Popen('ps -p %d -o rss,sz' % pid, shell=True,
                        stdout=PIPE).stdout.readlines()
         except OSError:
             raise NotImplementedError(
                 "report_memory works on Linux only if "
                 "the 'ps' program is found")
         mem = int(a2[1].split()[1])
-    elif sys.platform.startswith('darwin'):
+    elif sys.platform == 'darwin':
         try:
-            a2 = Popen(str('ps -p %d -o rss,vsz') % pid, shell=True,
+            a2 = Popen('ps -p %d -o rss,vsz' % pid, shell=True,
                        stdout=PIPE).stdout.readlines()
         except OSError:
             raise NotImplementedError(
                 "report_memory works on Mac OS only if "
                 "the 'ps' program is found")
         mem = int(a2[1].split()[0])
-    elif sys.platform.startswith('win'):
+    elif sys.platform == 'win32':
         try:
-            a2 = Popen([str("tasklist"), "/nh", "/fi", "pid eq %d" % pid],
+            a2 = Popen(["tasklist", "/nh", "/fi", "pid eq %d" % pid],
                        stdout=PIPE).stdout.read()
         except OSError:
             raise NotImplementedError(
diff --git a/setupext.py b/setupext.py
@@ -565,7 +565,7 @@ def _try_managers(*managers):
                            .format(url, self.name))
         elif sys.platform == "darwin":
             message = _try_managers("brew", "port")
-        elif sys.platform.startswith("linux"):
+        elif sys.platform == "linux":
             release = platform.linux_distribution()[0].lower()
             if release in ('debian', 'ubuntu'):
                 message = _try_managers('apt-get')
@@ -1421,7 +1421,7 @@ def add_flags(self, ext):
         if sys.platform == 'win32':
             # PSAPI library needed for finding Tcl / Tk at run time
             ext.libraries.extend(['psapi'])
-        elif sys.platform.startswith('linux'):
+        elif sys.platform == 'linux':
             ext.libraries.extend(['dl'])
 
 
