hub/venv/lib/python3.7/site-packages/IPython/utils/py3compat.py

192 lines
5.4 KiB
Python

# coding: utf-8
"""Compatibility tricks for Python 3. Mainly to do with unicode.
This file is deprecated and will be removed in a future version.
"""
import functools
import os
import sys
import re
import shutil
import types
import platform
from .encoding import DEFAULT_ENCODING
def decode(s, encoding=None):
encoding = encoding or DEFAULT_ENCODING
return s.decode(encoding, "replace")
def encode(u, encoding=None):
encoding = encoding or DEFAULT_ENCODING
return u.encode(encoding, "replace")
def cast_unicode(s, encoding=None):
if isinstance(s, bytes):
return decode(s, encoding)
return s
def cast_bytes(s, encoding=None):
if not isinstance(s, bytes):
return encode(s, encoding)
return s
def buffer_to_bytes(buf):
"""Cast a buffer object to bytes"""
if not isinstance(buf, bytes):
buf = bytes(buf)
return buf
def _modify_str_or_docstring(str_change_func):
@functools.wraps(str_change_func)
def wrapper(func_or_str):
if isinstance(func_or_str, (str,)):
func = None
doc = func_or_str
else:
func = func_or_str
doc = func.__doc__
# PYTHONOPTIMIZE=2 strips docstrings, so they can disappear unexpectedly
if doc is not None:
doc = str_change_func(doc)
if func:
func.__doc__ = doc
return func
return doc
return wrapper
def safe_unicode(e):
"""unicode(e) with various fallbacks. Used for exceptions, which may not be
safe to call unicode() on.
"""
try:
return str(e)
except UnicodeError:
pass
try:
return repr(e)
except UnicodeError:
pass
return u'Unrecoverably corrupt evalue'
# shutil.which from Python 3.4
def _shutil_which(cmd, mode=os.F_OK | os.X_OK, path=None):
"""Given a command, mode, and a PATH string, return the path which
conforms to the given mode on the PATH, or None if there is no such
file.
`mode` defaults to os.F_OK | os.X_OK. `path` defaults to the result
of os.environ.get("PATH"), or can be overridden with a custom search
path.
This is a backport of shutil.which from Python 3.4
"""
# Check that a given file can be accessed with the correct mode.
# Additionally check that `file` is not a directory, as on Windows
# directories pass the os.access check.
def _access_check(fn, mode):
return (os.path.exists(fn) and os.access(fn, mode)
and not os.path.isdir(fn))
# If we're given a path with a directory part, look it up directly rather
# than referring to PATH directories. This includes checking relative to the
# current directory, e.g. ./script
if os.path.dirname(cmd):
if _access_check(cmd, mode):
return cmd
return None
if path is None:
path = os.environ.get("PATH", os.defpath)
if not path:
return None
path = path.split(os.pathsep)
if sys.platform == "win32":
# The current directory takes precedence on Windows.
if not os.curdir in path:
path.insert(0, os.curdir)
# PATHEXT is necessary to check on Windows.
pathext = os.environ.get("PATHEXT", "").split(os.pathsep)
# See if the given file matches any of the expected path extensions.
# This will allow us to short circuit when given "python.exe".
# If it does match, only test that one, otherwise we have to try
# others.
if any(cmd.lower().endswith(ext.lower()) for ext in pathext):
files = [cmd]
else:
files = [cmd + ext for ext in pathext]
else:
# On other platforms you don't have things like PATHEXT to tell you
# what file suffixes are executable, so just pass on cmd as-is.
files = [cmd]
seen = set()
for dir in path:
normdir = os.path.normcase(dir)
if not normdir in seen:
seen.add(normdir)
for thefile in files:
name = os.path.join(dir, thefile)
if _access_check(name, mode):
return name
return None
PY3 = True
# keep reference to builtin_mod because the kernel overrides that value
# to forward requests to a frontend.
def input(prompt=''):
return builtin_mod.input(prompt)
builtin_mod_name = "builtins"
import builtins as builtin_mod
which = shutil.which
def isidentifier(s, dotted=False):
if dotted:
return all(isidentifier(a) for a in s.split("."))
return s.isidentifier()
getcwd = os.getcwd
MethodType = types.MethodType
def execfile(fname, glob, loc=None, compiler=None):
loc = loc if (loc is not None) else glob
with open(fname, 'rb') as f:
compiler = compiler or compile
exec(compiler(f.read(), fname, 'exec'), glob, loc)
# Refactor print statements in doctests.
_print_statement_re = re.compile(r"\bprint (?P<expr>.*)$", re.MULTILINE)
# Abstract u'abc' syntax:
@_modify_str_or_docstring
def u_format(s):
""""{u}'abc'" --> "'abc'" (Python 3)
Accepts a string or a function, so it can be used as a decorator."""
return s.format(u='')
PY2 = not PY3
PYPY = platform.python_implementation() == "PyPy"
# Cython still rely on that as a Dec 28 2019
# See https://github.com/cython/cython/pull/3291 and
# https://github.com/ipython/ipython/issues/12068
def no_code(x, encoding=None):
return x
unicode_to_str = cast_bytes_py2 = no_code