remove six: Replace six.string_types and six.integer_types, etc. (#541)

This commit includes:

* assuming Python 3 for test skipping
* assuming Python 3 for fire's various type checks
* assuming Python 3 for imports (like asyncio)
* assuming Python 3 for getting function signatures
* six is no longer considered a hidden module (and so if a user of fire has six in their globals when they call Fire(), six will now show up where it used to be hidden)

This commit does not remove six from console/ code.

fire/completion.py

@@ -23,7 +23,6 @@
 import inspect
 
 from fire import inspectutils
-import six
 
 
 def Script(name, component, default_options=None, shell='bash'):
@@ -308,18 +307,19 @@ def MemberVisible(component, name, member, class_attrs=None, verbose=False):
   Returns
     A boolean value indicating whether the member should be included.
   """
-  if isinstance(name, six.string_types) and name.startswith('__'):
+  if isinstance(name, str) and name.startswith('__'):
     return False
   if verbose:
     return True
   if (member is absolute_import
       or member is division
       or member is print_function):
     return False
-  if isinstance(member, type(absolute_import)) and six.PY34:
+  if isinstance(member, type(absolute_import)):
     return False
-  if inspect.ismodule(member) and member is six:
-    # TODO(dbieber): Determine more generally which modules to hide.
+  # TODO(dbieber): Determine more generally which modules to hide.
+  modules_to_hide = []
+  if inspect.ismodule(member) and member in modules_to_hide:
     return False
   if inspect.isclass(component):
     # If class_attrs has not been provided, compute it.
@@ -336,14 +336,7 @@ def MemberVisible(component, name, member, class_attrs=None, verbose=False):
       tuplegetter = getattr(collections, '_tuplegetter', type(None))
       if isinstance(class_attr.object, tuplegetter):
         return False
-  if (six.PY2 and inspect.isfunction(component)
-      and name in ('func_closure', 'func_code', 'func_defaults',
-                   'func_dict', 'func_doc', 'func_globals', 'func_name')):
-    return False
-  if (six.PY2 and inspect.ismethod(component)
-      and name in ('im_class', 'im_func', 'im_self')):
-    return False
-  if isinstance(name, six.string_types):
+  if isinstance(name, str):
     return not name.startswith('_')
   return True  # Default to including the member
 
@@ -438,7 +431,7 @@ def _FormatForCommand(token):
   Returns:
     The transformed token.
   """
-  if not isinstance(token, six.string_types):
+  if not isinstance(token, str):
     token = str(token)
 
   if token.startswith('_'):

fire/core.py

@@ -67,10 +67,8 @@ def main(argv):
 from fire import trace
 from fire import value_types
 from fire.console import console_io
-import six
 
-if six.PY34:
-  import asyncio  # pylint: disable=import-error,g-import-not-at-top  # pytype: disable=import-error
+import asyncio  # pylint: disable=import-error,g-import-not-at-top  # pytype: disable=import-error
 
 
 def Fire(component=None, command=None, name=None, serialize=None):
@@ -109,7 +107,7 @@ def Fire(component=None, command=None, name=None, serialize=None):
   name = name or os.path.basename(sys.argv[0])
 
   # Get args as a list.
-  if isinstance(command, six.string_types):
+  if isinstance(command, str):
     args = shlex.split(command)
   elif isinstance(command, (list, tuple)):
     args = command
@@ -344,7 +342,7 @@ def _DictAsString(result, verbose=False):
 def _OneLineResult(result):
   """Returns result serialized to a single line string."""
   # TODO(dbieber): Ensure line is fewer than eg 120 characters.
-  if isinstance(result, six.string_types):
+  if isinstance(result, str):
     return str(result).replace('\n', ' ')
 
   # TODO(dbieber): Show a small amount of usage information about the function

fire/core_test.py

@@ -20,8 +20,6 @@
 from fire import trace
 import mock
 
-import six
-
 
 class CoreTest(testutils.BaseTestCase):
 
@@ -214,13 +212,11 @@ def serialize(x):
     with self.assertRaises(core.FireError):
       core.Fire(ident, command=['asdf'], serialize=55)
 
-  @testutils.skipIf(six.PY2, 'lru_cache is Python 3 only.')
   def testLruCacheDecoratorBoundArg(self):
     self.assertEqual(
         core.Fire(tc.py3.LruCacheDecoratedMethod,  # pytype: disable=module-attr
                   command=['lru_cache_in_class', 'foo']), 'foo')
 
-  @testutils.skipIf(six.PY2, 'lru_cache is Python 3 only.')
   def testLruCacheDecorator(self):
     self.assertEqual(
         core.Fire(tc.py3.lru_cache_decorated,  # pytype: disable=module-attr

fire/custom_descriptions.py

@@ -37,7 +37,6 @@
 """
 
 from fire import formatting
-import six
 
 TWO_DOUBLE_QUOTES = '""'
 STRING_DESC_PREFIX = 'The string '
@@ -60,13 +59,11 @@ def NeedsCustomDescription(component):
     Whether the component should use a custom description and summary.
   """
   type_ = type(component)
-  if (type_ in six.string_types
-      or type_ in six.integer_types
-      or type_ is six.text_type
-      or type_ is six.binary_type
+  if (
+      type_ in (str, int, bytes)
       or type_ in (float, complex, bool)
       or type_ in (dict, tuple, list, set, frozenset)
-     ):
+  ):
     return True
   return False
 

fire/fire_test.py

@@ -22,7 +22,6 @@
 from fire import testutils
 
 import mock
-import six
 
 
 class FireTest(testutils.BaseTestCase):
@@ -180,7 +179,6 @@ def testFireAnnotatedArgs(self):
     self.assertEqual(fire.Fire(tc.Annotations, command=['double', '5']), 10)
     self.assertEqual(fire.Fire(tc.Annotations, command=['triple', '5']), 15)
 
-  @testutils.skipIf(six.PY2, 'Keyword-only arguments not in Python 2.')
   def testFireKeywordOnlyArgs(self):
     with self.assertRaisesFireExit(2):
       # Keyword arguments must be passed with flag syntax.
@@ -717,7 +715,6 @@ def testHelpKwargsDecorator(self):
     with self.assertRaisesFireExit(0):
       fire.Fire(tc.decorated_method, command=['--help'])
 
-  @testutils.skipIf(six.PY2, 'Asyncio not available in Python 2.')
   def testFireAsyncio(self):
     self.assertEqual(fire.Fire(tc.py3.WithAsyncio,
                                command=['double', '--count', '10']), 20)

fire/helptext_test.py

@@ -23,7 +23,6 @@
 from fire import test_components as tc
 from fire import testutils
 from fire import trace
-import six
 
 
 class HelpTest(testutils.BaseTestCase):
@@ -276,27 +275,20 @@ def testHelpTextNoInit(self):
     self.assertIn('NAME\n    OldStyleEmpty', help_screen)
     self.assertIn('SYNOPSIS\n    OldStyleEmpty', help_screen)
 
-  @testutils.skipIf(
-      six.PY2, 'Python 2 does not support keyword-only arguments.')
   def testHelpTextKeywordOnlyArgumentsWithDefault(self):
     component = tc.py3.KeywordOnly.with_default  # pytype: disable=module-attr
     output = helptext.HelpText(
         component=component, trace=trace.FireTrace(component, 'with_default'))
     self.assertIn('NAME\n    with_default', output)
     self.assertIn('FLAGS\n    -x, --x=X', output)
 
-  @testutils.skipIf(
-      six.PY2, 'Python 2 does not support keyword-only arguments.')
   def testHelpTextKeywordOnlyArgumentsWithoutDefault(self):
     component = tc.py3.KeywordOnly.double  # pytype: disable=module-attr
     output = helptext.HelpText(
         component=component, trace=trace.FireTrace(component, 'double'))
     self.assertIn('NAME\n    double', output)
     self.assertIn('FLAGS\n    -c, --count=COUNT (required)', output)
 
-  @testutils.skipIf(
-      six.PY2,
-      'Python 2 does not support required name-only arguments.')
   def testHelpTextFunctionMixedDefaults(self):
     component = tc.py3.HelpTextComponent().identity
     t = trace.FireTrace(component, name='FunctionMixedDefaults')
@@ -523,9 +515,6 @@ def testUsageOutputFunctionWithDocstring(self):
         textwrap.dedent(expected_output).lstrip('\n'),
         usage_output)
 
-  @testutils.skipIf(
-      six.PY2,
-      'Python 2 does not support required name-only arguments.')
   def testUsageOutputFunctionMixedDefaults(self):
     component = tc.py3.HelpTextComponent().identity
     t = trace.FireTrace(component, name='FunctionMixedDefaults')

fire/inspectutils.py

@@ -20,10 +20,7 @@
 
 from fire import docstrings
 
-import six
-
-if six.PY34:
-  import asyncio  # pylint: disable=import-error,g-import-not-at-top  # pytype: disable=import-error
+import asyncio  # pylint: disable=import-error,g-import-not-at-top  # pytype: disable=import-error
 
 
 class FullArgSpec(object):
@@ -74,8 +71,6 @@ class with an __init__ method.
   if inspect.isclass(fn):
     # If the function is a class, we try to use its init method.
     skip_arg = True
-    if six.PY2 and hasattr(fn, '__init__'):
-      fn = fn.__init__
   elif inspect.ismethod(fn):
     # If the function is a bound method, we skip the `self` argument.
     skip_arg = fn.__self__ is not None
@@ -91,16 +86,6 @@ class with an __init__ method.
   return fn, skip_arg
 
 
-def Py2GetArgSpec(fn):
-  """A wrapper around getargspec that tries both fn and fn.__call__."""
-  try:
-    return inspect.getargspec(fn)  # pylint: disable=deprecated-method,no-member
-  except TypeError:
-    if hasattr(fn, '__call__'):
-      return inspect.getargspec(fn.__call__)  # pylint: disable=deprecated-method,no-member
-    raise
-
-
 def Py3GetFullArgSpec(fn):
   """A alternative to the builtin getfullargspec.
 
@@ -185,13 +170,9 @@ def GetFullArgSpec(fn):
     if sys.version_info[0:2] >= (3, 5):
       (args, varargs, varkw, defaults,
        kwonlyargs, kwonlydefaults, annotations) = Py3GetFullArgSpec(fn)
-    elif six.PY3:  # Specifically Python 3.4.
+    else:  # Specifically Python 3.4.
       (args, varargs, varkw, defaults,
        kwonlyargs, kwonlydefaults, annotations) = inspect.getfullargspec(fn)  # pylint: disable=deprecated-method,no-member
-    else:  # six.PY2
-      args, varargs, varkw, defaults = Py2GetArgSpec(fn)
-      kwonlyargs = kwonlydefaults = None
-      annotations = getattr(fn, '__annotations__', None)
 
   except TypeError:
     # If we can't get the argspec, how do we know if the fn should take args?
@@ -221,7 +202,7 @@ def GetFullArgSpec(fn):
     return FullArgSpec()
 
   # In Python 3.5+ Py3GetFullArgSpec uses skip_bound_arg=True already.
-  skip_arg_required = six.PY2 or sys.version_info[0:2] == (3, 4)
+  skip_arg_required = sys.version_info[0:2] == (3, 4)
   if skip_arg_required and skip_arg and args:
     args.pop(0)  # Remove 'self' or 'cls' from the list of arguments.
   return FullArgSpec(args, varargs, varkw, defaults,
@@ -363,6 +344,6 @@ def GetClassAttrsDict(component):
 
 def IsCoroutineFunction(fn):
   try:
-    return six.PY34 and asyncio.iscoroutinefunction(fn)
+    return asyncio.iscoroutinefunction(fn)
   except:  # pylint: disable=bare-except
     return False

fire/inspectutils_test.py

@@ -15,14 +15,11 @@
 """Tests for the inspectutils module."""
 
 import os
-import unittest
 
 from fire import inspectutils
 from fire import test_components as tc
 from fire import testutils
 
-import six
-
 
 class InspectUtilsTest(testutils.BaseTestCase):
 
@@ -36,7 +33,6 @@ def testGetFullArgSpec(self):
     self.assertEqual(spec.kwonlydefaults, {})
     self.assertEqual(spec.annotations, {'arg2': int, 'arg4': int})
 
-  @unittest.skipIf(six.PY2, 'No keyword arguments in python 2')
   def testGetFullArgSpecPy3(self):
     spec = inspectutils.GetFullArgSpec(tc.py3.identity)
     self.assertEqual(spec.args, ['arg1', 'arg2', 'arg3', 'arg4'])
@@ -121,10 +117,7 @@ def testInfoClass(self):
 
   def testInfoClassNoInit(self):
     info = inspectutils.Info(tc.OldStyleEmpty)
-    if six.PY2:
-      self.assertEqual(info.get('type_name'), 'classobj')
-    else:
-      self.assertEqual(info.get('type_name'), 'type')
+    self.assertEqual(info.get('type_name'), 'type')
     self.assertIn(os.path.join('fire', 'test_components.py'), info.get('file'))
     self.assertGreater(info.get('line'), 0)
 

fire/parser_fuzz_test.py

@@ -21,7 +21,6 @@
 from hypothesis import settings
 from hypothesis import strategies as st
 import Levenshtein
-import six
 
 
 class ParserFuzzTest(testutils.BaseTestCase):
@@ -64,8 +63,8 @@ def testDefaultParseValueFuzz(self, value):
       raise
 
     try:
-      uvalue = six.text_type(value)
-      uresult = six.text_type(result)
+      uvalue = str(value)
+      uresult = str(result)
     except UnicodeDecodeError:
       # This is not what we're testing.
       return
@@ -82,7 +81,7 @@ def testDefaultParseValueFuzz(self, value):
     if '#' in value:
       max_distance += len(value) - value.index('#')
 
-    if not isinstance(result, six.string_types):
+    if not isinstance(result, str):
       max_distance += value.count('0')  # Leading 0s are stripped.
 
     # Note: We don't check distance for dicts since item order can be changed.

fire/test_components.py

@@ -18,10 +18,7 @@
 import enum
 import functools
 
-import six
-
-if six.PY3:
-  from fire import test_components_py3 as py3  # pylint: disable=unused-import,no-name-in-module,g-import-not-at-top
+from fire import test_components_py3 as py3  # pylint: disable=unused-import,no-name-in-module,g-import-not-at-top
 
 
 def identity(arg1, arg2, arg3=10, arg4=20, *arg5, **arg6):  # pylint: disable=keyword-arg-before-vararg

fire/testutils.py

@@ -15,6 +15,7 @@
 """Utilities for Python Fire's tests."""
 
 import contextlib
+import io
 import os
 import re
 import sys
@@ -24,7 +25,6 @@
 from fire import trace
 
 import mock
-import six
 
 
 class BaseTestCase(unittest.TestCase):
@@ -45,8 +45,8 @@ def assertOutputMatches(self, stdout='.*', stderr='.*', capture=True):
     Yields:
       Yields to the wrapped context.
     """
-    stdout_fp = six.StringIO()
-    stderr_fp = six.StringIO()
+    stdout_fp = io.StringIO()
+    stderr_fp = io.StringIO()
     try:
       with mock.patch.object(sys, 'stdout', stdout_fp):
         with mock.patch.object(sys, 'stderr', stderr_fp):
@@ -69,10 +69,7 @@ def assertOutputMatches(self, stdout='.*', stderr='.*', capture=True):
                                (name, value, regexp))
 
   def assertRaisesRegex(self, *args, **kwargs):  # pylint: disable=arguments-differ
-    if sys.version_info.major == 2:
-      return super(BaseTestCase, self).assertRaisesRegexp(*args, **kwargs)  # pylint: disable=deprecated-method,no-member
-    else:
-      return super(BaseTestCase, self).assertRaisesRegex(*args, **kwargs)  # pylint: disable=no-member
+    return super(BaseTestCase, self).assertRaisesRegex(*args, **kwargs)  # pylint: disable=no-member
 
   @contextlib.contextmanager
   def assertRaisesFireExit(self, code, regexp='.*'):