Continue upgrade of codebase to Python 3 (#556)

Obtained with pyupgrade, reverting any changes that remove a module we still depend on.
`uv run pyupgrade **/**.py --py3-plus`

fire/__main__.py

@@ -54,14 +54,14 @@ def import_from_file_path(path):
   """
 
   if not os.path.exists(path):
-    raise IOError('Given file path does not exist.')
+    raise OSError('Given file path does not exist.')
 
   module_name = os.path.basename(path)
 
   spec = util.spec_from_file_location(module_name, path)
 
   if spec is None:
-    raise IOError('Unable to load module from specified path.')
+    raise OSError('Unable to load module from specified path.')
 
   module = util.module_from_spec(spec)  # pylint: disable=no-member
   spec.loader.exec_module(module)  # pytype: disable=attribute-error
@@ -104,7 +104,7 @@ def import_module(module_or_filename):
     return import_from_file_path(module_or_filename)
 
   if os.path.sep in module_or_filename:  # Use / to detect if it was a filename.
-    raise IOError('Fire was passed a filename which could not be found.')
+    raise OSError('Fire was passed a filename which could not be found.')
 
   return import_from_module_name(module_or_filename)  # Assume it's a module.
 

fire/core.py

@@ -199,7 +199,7 @@ def __init__(self, code, component_trace):
       code: (int) Exit code for the Fire CLI.
       component_trace: (FireTrace) The trace for the Fire command.
     """
-    super(FireExit, self).__init__(code)
+    super().__init__(code)
     self.trace = component_trace
 
 

fire/decorators_test.py

@@ -19,7 +19,7 @@
 from fire import testutils
 
 
-class NoDefaults(object):
+class NoDefaults:
   """A class for testing decorated functions without default values."""
 
   @decorators.SetParseFns(count=int)
@@ -40,7 +40,7 @@ def double(count):
   return 2 * count
 
 
-class WithDefaults(object):
+class WithDefaults:
 
   @decorators.SetParseFns(float)
   def example1(self, arg1=10):
@@ -51,14 +51,14 @@ def example2(self, arg1=10):
     return arg1, type(arg1)
 
 
-class MixedArguments(object):
+class MixedArguments:
 
   @decorators.SetParseFns(float, arg2=str)
   def example3(self, arg1, arg2):
     return arg1, arg2
 
 
-class PartialParseFn(object):
+class PartialParseFn:
 
   @decorators.SetParseFns(arg1=str)
   def example4(self, arg1, arg2):
@@ -69,7 +69,7 @@ def example5(self, arg1, arg2):
     return arg1, arg2
 
 
-class WithKwargs(object):
+class WithKwargs:
 
   @decorators.SetParseFns(mode=str, count=int)
   def example6(self, **kwargs):
@@ -79,7 +79,7 @@ def example6(self, **kwargs):
     )
 
 
-class WithVarArgs(object):
+class WithVarArgs:
 
   @decorators.SetParseFn(str)
   def example7(self, arg1, arg2=None, *varargs, **kwargs):  # pylint: disable=keyword-arg-before-vararg

fire/helptext.py

@@ -767,7 +767,7 @@ def _CreateAvailabilityLine(header, items,
   return indented_header + indented_items_text[len(indented_header):] + '\n'
 
 
-class ActionGroup(object):
+class ActionGroup:
   """A group of actions of the same kind."""
 
   def __init__(self, name, plural):

fire/helptext_test.py

@@ -27,7 +27,7 @@
 class HelpTest(testutils.BaseTestCase):
 
   def setUp(self):
-    super(HelpTest, self).setUp()
+    super().setUp()
     os.environ['ANSI_COLORS_DISABLED'] = '1'
 
   def testHelpTextNoDefaults(self):

fire/inspectutils.py

@@ -22,7 +22,7 @@
 from fire import docstrings
 
 
-class FullArgSpec(object):
+class FullArgSpec:
   """The arguments of a function, as in Python 3's inspect.FullArgSpec."""
 
   def __init__(self, args=None, varargs=None, varkw=None, defaults=None,
@@ -229,7 +229,7 @@ def GetFileAndLine(component):
   try:
     unused_code, lineindex = inspect.findsource(component)
     lineno = lineindex + 1
-  except (IOError, IndexError):
+  except (OSError, IndexError):
     lineno = None
 
   return filename, lineno
@@ -268,7 +268,7 @@ def Info(component):
   try:
     unused_code, lineindex = inspect.findsource(component)
     info['line'] = lineindex + 1
-  except (TypeError, IOError):
+  except (TypeError, OSError):
     info['line'] = None
 
   if 'docstring' in info:

fire/main_test.py

@@ -43,7 +43,7 @@ class MainModuleFileTest(testutils.BaseTestCase):
   """Tests to verify correct import behavior for file executables."""
 
   def setUp(self):
-    super(MainModuleFileTest, self).setUp()
+    super().setUp()
     self.file = tempfile.NamedTemporaryFile(suffix='.py')  # pylint: disable=consider-using-with
     self.file.write(b'class Foo:\n  def double(self, n):\n    return 2 * n\n')
     self.file.flush()

fire/parser_fuzz_test.py

@@ -53,7 +53,7 @@ def testDefaultParseValueFuzz(self, value):
       result = parser.DefaultParseValue(value)
     except TypeError:
       # It's OK to get a TypeError if the string has the null character.
-      if u'\x00' in value:
+      if '\x00' in value:
         return
       raise
     except MemoryError: