refactor(configuration.py): Shift the code to a module level function1

src/pip/_internal/commands/configuration.py

@@ -4,7 +4,7 @@
 import shutil
 import subprocess
 
-from pip._vendor.six import PY3
+from pip._vendor.six import PY2
 
 from pip._internal.cli.base_command import Command
 from pip._internal.cli.status_codes import ERROR, SUCCESS
@@ -27,6 +27,19 @@
 logger = logging.getLogger(__name__)
 
 
+def parse_editor_value(editor):
+ # type: (str) -> List[str]
+
+ if PY2:
+ return [editor]
+ result = shutil.which(editor)
+ if result:
+ return [result]
+ if os.path.exists(editor):
+ return [editor]
+ return shlex.split(editor)
+
+
 class ConfigurationCommand(Command):
  """
  Manage local and global configuration.
@@ -235,38 +248,20 @@ def print_env_var_values(self):
  def open_in_editor(self, options, args):
  # type: (Values, List[str]) -> None
  editor = self._determine_editor(options)
+ editor_command = parse_editor_value(editor)
 
  fname = self.configuration.get_file_to_edit()
  if fname is None:
  raise PipError("Could not determine appropriate file.")
 
  try:
- if PY3:
- # Since Python2 doesn't support shutil.which(), we only support
- # editor args for Python 3.
- args = self._get_editor_cmd(editor)
- else:
- args = [editor]
- args.append(fname)
- subprocess.check_call(args)
+ subprocess.check_call(editor_command + [fname])
  except subprocess.CalledProcessError as e:
  raise PipError(
  "Editor Subprocess exited with exit code {}"
  .format(e.returncode)
  )
 
- def _get_editor_cmd(self, editor):
- # type: (str) -> List[str]
-
- # Currently mypy fails for Python2 as it could not recognise the
- # shutil.which()
- result = shutil.which(editor) # type: ignore
- if result:
- return [result]
- if os.path.exists(editor):
- return [editor]
- return shlex.split(editor)
-
  def _get_n_args(self, args, example, n):
  # type: (List[str], str, int) -> Any
  """Helper to make sure the command got the right number of arguments