diff --git a/pip/__init__.py b/pip/__init__.py
index c38a31d7c32..99fa932637e 100644
--- a/pip/__init__.py
+++ b/pip/__init__.py
@@ -51,7 +51,6 @@
     InsecureRequestWarning,
 )
 
-
 # assignment for flake8 to be happy
 
 # This fixes a peculiarity when importing via __import__ - as we are
diff --git a/pip/basecommand.py b/pip/basecommand.py
index c1cc308af3f..3692e7caac4 100644
--- a/pip/basecommand.py
+++ b/pip/basecommand.py
@@ -249,6 +249,7 @@ def main(self, args):
                 )
                 with session:
                     pip_version_check(session, options)
+
             # Avoid leaking loggers
             for handler in set(logging.root.handlers) - original_root_handlers:
                 # this method benefit from the Logger class internal lock
@@ -270,8 +271,8 @@ def populate_requirement_set(requirement_set, args, options, finder,
 
         for filename in options.constraints:
             parsed_constraints = parse_requirements(
-                    filename,
-                    constraint=True, finder=finder, options=options,
+                filename,
+                constraint=True, finder=finder, options=options,
                 session=session, wheel_cache=wheel_cache
             )
             for req in parsed_constraints:
diff --git a/pip/baseparser.py b/pip/baseparser.py
index ea76a21afeb..93864b60fbb 100644
--- a/pip/baseparser.py
+++ b/pip/baseparser.py
@@ -203,6 +203,7 @@ def _update_defaults(self, defaults):
                 late_eval.add(option.dest)
                 opt_str = option.get_opt_string()
                 val = option.convert_value(opt_str, val)
+
                 # From take_action
                 args = option.callback_args or ()
                 kwargs = option.callback_kwargs or {}
@@ -214,6 +215,7 @@ def _update_defaults(self, defaults):
 
         for key in late_eval:
             defaults[key] = getattr(self.values, key)
+
         self.values = None
         return defaults
 
@@ -230,6 +232,7 @@ def get_default_values(self):
             if isinstance(default, string_types):
                 opt_str = option.get_opt_string()
                 defaults[option.dest] = option.check_value(opt_str, default)
+
         return optparse.Values(defaults)
 
     def error(self, msg):
diff --git a/pip/commands/show.py b/pip/commands/show.py
index c3c957c4f27..ff5e4a104d8 100644
--- a/pip/commands/show.py
+++ b/pip/commands/show.py
@@ -165,4 +165,5 @@ def print_results(distributions, list_files=False, verbose=False):
                 logger.info("  %s", line.strip())
             if "files" not in dist:
                 logger.info("Cannot locate installed-files.txt")
+
     return results_printed
diff --git a/pip/commands/uninstall.py b/pip/commands/uninstall.py
index a2654cedca1..3b3e31e0f2d 100644
--- a/pip/commands/uninstall.py
+++ b/pip/commands/uninstall.py
@@ -61,11 +61,13 @@ def run(self, options, args):
                 for req in parsed_reqs:
                     if req.name:
                         reqs_to_uninstall[canonicalize_name(req.name)] = req
+
             if not reqs_to_uninstall:
                 raise InstallationError(
                     'You must give at least one requirement to %(name)s (see '
                     '"pip help %(name)s")' % dict(name=self.name)
                 )
+
             for req in reqs_to_uninstall.values():
                 verbose = options.verbose != 0
                 req.uninstall(auto_confirm=options.yes, verbose=verbose)
diff --git a/pip/operations/prepare.py b/pip/operations/prepare.py
index 2dea4b14dcb..2481db3f21e 100644
--- a/pip/operations/prepare.py
+++ b/pip/operations/prepare.py
@@ -189,12 +189,12 @@ def _prepare_linked_requirement(self, req, resolver):
             # occurs when the script attempts to unpack the
             # build directory
             req.ensure_has_source_dir(self.build_dir)
+
             # If a checkout exists, it's unwise to keep going.  version
             # inconsistencies are logged later, but do not fail the
             # installation.
             # FIXME: this won't upgrade when there's an existing
             # package unpacked in `req.source_dir`
-            # package unpacked in `req.source_dir`
             if os.path.exists(os.path.join(req.source_dir, 'setup.py')):
                 raise PreviousBuildDirError(
                     "pip can't proceed with requirements '%s' due to a"