bpo-30152: Reduce the number of imports for argparse. (#1269)

This commit is contained in:
Serhiy Storchaka 2017-09-26 00:55:55 +03:00 committed by GitHub
parent f1502d097c
commit 81108375d9
8 changed files with 59 additions and 49 deletions

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@ -84,15 +84,12 @@ __all__ = [
import collections as _collections
import copy as _copy
import os as _os
import re as _re
import sys as _sys
import textwrap as _textwrap
from gettext import gettext as _, ngettext
SUPPRESS = '==SUPPRESS=='
OPTIONAL = '?'
@ -137,10 +134,16 @@ class _AttributeHolder(object):
return []
def _ensure_value(namespace, name, value):
if getattr(namespace, name, None) is None:
setattr(namespace, name, value)
return getattr(namespace, name)
def _copy_items(items):
if items is None:
return []
# The copy module is used only in the 'append' and 'append_const'
# actions, and it is needed only when the default value isn't a list.
# Delay its import for speeding up the common case.
if type(items) is list:
return items[:]
import copy
return copy.copy(items)
# ===============
@ -619,12 +622,17 @@ class HelpFormatter(object):
def _split_lines(self, text, width):
text = self._whitespace_matcher.sub(' ', text).strip()
return _textwrap.wrap(text, width)
# The textwrap module is used only for formatting help.
# Delay its import for speeding up the common usage of argparse.
import textwrap
return textwrap.wrap(text, width)
def _fill_text(self, text, width, indent):
text = self._whitespace_matcher.sub(' ', text).strip()
return _textwrap.fill(text, width, initial_indent=indent,
subsequent_indent=indent)
import textwrap
return textwrap.fill(text, width,
initial_indent=indent,
subsequent_indent=indent)
def _get_help_string(self, action):
return action.help
@ -952,7 +960,8 @@ class _AppendAction(Action):
metavar=metavar)
def __call__(self, parser, namespace, values, option_string=None):
items = _copy.copy(_ensure_value(namespace, self.dest, []))
items = getattr(namespace, self.dest, None)
items = _copy_items(items)
items.append(values)
setattr(namespace, self.dest, items)
@ -978,7 +987,8 @@ class _AppendConstAction(Action):
metavar=metavar)
def __call__(self, parser, namespace, values, option_string=None):
items = _copy.copy(_ensure_value(namespace, self.dest, []))
items = getattr(namespace, self.dest, None)
items = _copy_items(items)
items.append(self.const)
setattr(namespace, self.dest, items)
@ -1000,8 +1010,10 @@ class _CountAction(Action):
help=help)
def __call__(self, parser, namespace, values, option_string=None):
new_count = _ensure_value(namespace, self.dest, 0) + 1
setattr(namespace, self.dest, new_count)
count = getattr(namespace, self.dest, None)
if count is None:
count = 0
setattr(namespace, self.dest, count + 1)
class _HelpAction(Action):

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@ -1,7 +1,5 @@
import sys
from types import MappingProxyType, DynamicClassAttribute
from functools import reduce
from operator import or_ as _or_
# try _collections first to reduce startup cost
try:
@ -744,11 +742,10 @@ class Flag(Enum):
def __invert__(self):
members, uncovered = _decompose(self.__class__, self._value_)
inverted_members = [
m for m in self.__class__
if m not in members and not m._value_ & self._value_
]
inverted = reduce(_or_, inverted_members, self.__class__(0))
inverted = self.__class__(0)
for m in self.__class__:
if m not in members and not (m._value_ & self._value_):
inverted = inverted | m
return self.__class__(inverted)

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@ -46,13 +46,10 @@ internationalized, to the local language and cultural habits.
# find this format documented anywhere.
import copy
import locale
import os
import re
import struct
import sys
from errno import ENOENT
__all__ = ['NullTranslations', 'GNUTranslations', 'Catalog',
@ -342,7 +339,9 @@ class GNUTranslations(NullTranslations):
def _parse(self, fp):
"""Override this method to support alternative .mo formats."""
unpack = struct.unpack
# Delay struct import for speeding up gettext import when .mo files
# are not used.
from struct import unpack
filename = getattr(fp, 'name', '')
# Parse the .mo file header, which consists of 5 little endian 32
# bit words.
@ -520,7 +519,9 @@ def translation(domain, localedir=None, languages=None,
if not mofiles:
if fallback:
return NullTranslations()
raise OSError(ENOENT, 'No translation file found for domain', domain)
from errno import ENOENT
raise FileNotFoundError(ENOENT,
'No translation file found for domain', domain)
# Avoid opening, reading, and parsing the .mo file after it's been done
# once.
result = None
@ -533,6 +534,9 @@ def translation(domain, localedir=None, languages=None,
# Copy the translation object to allow setting fallbacks and
# output charset. All other instance data is shared with the
# cached object.
# Delay copy import for speeding up gettext import when .mo files
# are not used.
import copy
t = copy.copy(t)
if codeset:
t.set_output_charset(codeset)

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@ -14,10 +14,9 @@ import sys
import encodings
import encodings.aliases
import re
import collections.abc
import _collections_abc
from builtins import str as _builtin_str
import functools
import warnings
# Try importing the _locale module.
#
@ -215,7 +214,7 @@ def format_string(f, val, grouping=False, monetary=False):
percents = list(_percent_re.finditer(f))
new_f = _percent_re.sub('%s', f)
if isinstance(val, collections.abc.Mapping):
if isinstance(val, _collections_abc.Mapping):
new_val = []
for perc in percents:
if perc.group()[-1]=='%':
@ -244,6 +243,7 @@ def format_string(f, val, grouping=False, monetary=False):
def format(percent, value, grouping=False, monetary=False, *additional):
"""Deprecated, use format_string instead."""
import warnings
warnings.warn(
"This method will be removed in a future version of Python. "
"Use 'locale.format_string()' instead.",

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@ -23,7 +23,7 @@ and opendir), and leave all pathname manipulation to os.path
#'
import abc
import sys, errno
import sys
import stat as st
_names = sys.builtin_module_names
@ -590,12 +590,10 @@ def _execvpe(file, args, env=None):
argrest = (args,)
env = environ
head, tail = path.split(file)
if head:
if path.dirname(file):
exec_func(file, *argrest)
return
last_exc = saved_exc = None
saved_tb = None
saved_exc = None
path_list = get_exec_path(env)
if name != 'nt':
file = fsencode(file)
@ -604,16 +602,15 @@ def _execvpe(file, args, env=None):
fullname = path.join(dir, file)
try:
exec_func(fullname, *argrest)
except (FileNotFoundError, NotADirectoryError) as e:
last_exc = e
except OSError as e:
last_exc = e
tb = sys.exc_info()[2]
if (e.errno != errno.ENOENT and e.errno != errno.ENOTDIR
and saved_exc is None):
if saved_exc is None:
saved_exc = e
saved_tb = tb
if saved_exc:
raise saved_exc.with_traceback(saved_tb)
raise last_exc.with_traceback(tb)
if saved_exc is not None:
raise saved_exc
raise last_exc
def get_exec_path(env=None):

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@ -6,7 +6,7 @@ import os
import posixpath
import re
import sys
from collections.abc import Sequence
from _collections_abc import Sequence
from errno import EINVAL, ENOENT, ENOTDIR
from operator import attrgetter
from stat import S_ISDIR, S_ISLNK, S_ISREG, S_ISSOCK, S_ISBLK, S_ISCHR, S_ISFIFO

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@ -172,9 +172,6 @@ class DynamicClassAttribute:
return result
import functools as _functools
import collections.abc as _collections_abc
class _GeneratorWrapper:
# TODO: Implement this in C.
def __init__(self, gen):
@ -247,7 +244,10 @@ def coroutine(func):
# return generator-like objects (for instance generators
# compiled with Cython).
@_functools.wraps(func)
# Delay functools and _collections_abc import for speeding up types import.
import functools
import _collections_abc
@functools.wraps(func)
def wrapped(*args, **kwargs):
coro = func(*args, **kwargs)
if (coro.__class__ is CoroutineType or

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@ -21,7 +21,7 @@ from _weakref import (
from _weakrefset import WeakSet, _IterationGuard
import collections.abc # Import after _weakref to avoid circular import.
import _collections_abc # Import after _weakref to avoid circular import.
import sys
import itertools
@ -87,7 +87,7 @@ class WeakMethod(ref):
__hash__ = ref.__hash__
class WeakValueDictionary(collections.abc.MutableMapping):
class WeakValueDictionary(_collections_abc.MutableMapping):
"""Mapping class that references values weakly.
Entries in the dictionary will be discarded when no strong
@ -340,7 +340,7 @@ class KeyedRef(ref):
super().__init__(ob, callback)
class WeakKeyDictionary(collections.abc.MutableMapping):
class WeakKeyDictionary(_collections_abc.MutableMapping):
""" Mapping class that references keys weakly.
Entries in the dictionary will be discarded when there is no