Fix flake8-return warnings (#4169)

Author: abravalheri

_distutils_hack/__init__.py

@@ -83,15 +83,15 @@ def find_spec(self, fullname, path, target=None):
         # optimization: only consider top level modules and those
         # found in the CPython test suite.
         if path is not None and not fullname.startswith('test.'):
-            return
+            return None
 
         method_name = 'spec_for_{fullname}'.format(**locals())
         method = getattr(self, method_name, lambda: None)
         return method()
 
     def spec_for_distutils(self):
         if self.is_cpython():
-            return
+            return None
 
         import importlib
         import importlib.abc
@@ -108,7 +108,7 @@ def spec_for_distutils(self):
             #   setuptools from the path but only after the hook
             #   has been loaded. Ref #2980.
             # In either case, fall back to stdlib behavior.
-            return
+            return None
 
         class DistutilsLoader(importlib.abc.Loader):
             def create_module(self, spec):

pkg_resources/__init__.py

@@ -1127,8 +1127,7 @@ def obtain(self, requirement, installer=None):
         None is returned instead.  This method is a hook that allows subclasses
         to attempt other ways of obtaining a distribution before falling back
         to the `installer` argument."""
-        if installer is not None:
-            return installer(requirement)
+        return installer(requirement) if installer else None
 
     def __iter__(self):
         """Yield the unique project names of the available distributions"""
@@ -2833,9 +2832,7 @@ def _get_metadata(self, name):
 
     def _get_version(self):
         lines = self._get_metadata(self.PKG_INFO)
-        version = _version_from_file(lines)
-
-        return version
+        return _version_from_file(lines)
 
     def activate(self, path=None, replace=False):
         """Ensure distribution is importable on `path` (default=sys.path)"""
@@ -3210,6 +3207,7 @@ def _find_adapter(registry, ob):
     for t in types:
         if t in registry:
             return registry[t]
+    return None
 
 
 def ensure_directory(path):

setuptools/command/bdist_egg.py

@@ -419,6 +419,7 @@ def can_scan():
         "Please ask the author to include a 'zip_safe'"
         " setting (either True or False) in the package's setup.py"
     )
+    return False
 
 
 # Attribute names of options for commands that might need to be convinced to

setuptools/command/bdist_rpm.py

@@ -30,11 +30,10 @@ def run(self):
 
     def _make_spec_file(self):
         spec = orig.bdist_rpm._make_spec_file(self)
-        spec = [
+        return [
             line.replace(
                 "setup.py install ",
                 "setup.py install --single-version-externally-managed ",
             ).replace("%setup", "%setup -n %{name}-%{unmangled_version}")
             for line in spec
         ]
-        return spec

setuptools/command/build_ext.py

@@ -76,6 +76,7 @@ def get_abi3_suffix():
             return suffix
         elif suffix == '.pyd':  # Windows
             return suffix
+    return None
 
 
 class build_ext(_build_ext):

setuptools/command/develop.py

@@ -157,6 +157,8 @@ def install_egg_scripts(self, dist):
                 script_text = strm.read()
             self.install_script(dist, script_name, script_text, script_path)
 
+        return None
+
     def install_wrapper_scripts(self, dist):
         dist = VersionlessRequirement(dist)
         return easy_install.install_wrapper_scripts(self, dist)

setuptools/command/easy_install.py

@@ -741,6 +741,7 @@ def install_item(self, spec, download, tmpdir, deps, install_needed=False):
             for dist in dists:
                 if dist in spec:
                     return dist
+        return None
 
     def select_scheme(self, name):
         try:
@@ -1473,9 +1474,7 @@ def get_site_dirs():
     with contextlib.suppress(AttributeError):
         sitedirs.extend(site.getsitepackages())
 
-    sitedirs = list(map(normalize_path, sitedirs))
-
-    return sitedirs
+    return list(map(normalize_path, sitedirs))
 
 
 def expand_paths(inputs):  # noqa: C901  # is too complex (11)  # FIXME

setuptools/command/install.py

@@ -71,6 +71,7 @@ def handle_extra_path(self):
         # command without --root or --single-version-externally-managed
         self.path_file = None
         self.extra_dirs = ''
+        return None
 
     def run(self):
         # Explicit request for old-style install?  Just do it
@@ -83,6 +84,8 @@ def run(self):
         else:
             self.do_egg_install()
 
+        return None
+
     @staticmethod
     def _called_from_setup(run_frame):
         """
@@ -114,6 +117,8 @@ def _called_from_setup(run_frame):
 
             return caller_module == 'distutils.dist' and info.function == 'run_commands'
 
+        return False
+
     def do_egg_install(self):
         easy_install = self.distribution.get_command_class('easy_install')
 

setuptools/depends.py

@@ -159,6 +159,7 @@ def extract_constant(code, symbol, default=-1):
         else:
             const = default
 
+    return None
 
 def _update_globals():
     """

setuptools/discovery.py

@@ -485,7 +485,7 @@ def analyse_name(self):
         """
         if self.dist.metadata.name or self.dist.name:
             # get_name() is not reliable (can return "UNKNOWN")
-            return None
+            return
 
         log.debug("No `name` configuration, performing automatic discovery")