to_native_string(string, encoding='ascii')：py2 py3编码问题
unicode_is_ascii(u_string)：判断unicode字符串是否只包含ASCII字符
# -*- coding: utf-8 -*-
"""
requests._internal_utils
~~~~~~~~~~~~~~
Provides utility functions that are consumed internally by Requests
which depend on extremely few external helpers (such as compat)
"""
from .compat import is_py2, builtin_str, str
def to_native_string(string, encoding='ascii'):
"""Given a string object, regardless of type, returns a representation of
that string in the native string type, encoding and decoding where
necessary. This assumes ASCII unless told otherwise.
"""
if isinstance(string, builtin_str):
out = string
else:
if is_py2:
out = string.encode(encoding)
else:
out = string.decode(encoding)
return out
def unicode_is_ascii(u_string):
"""Determine if unicode string only contains ASCII characters.
:param str u_string: unicode string to check. Must be unicode
and not Python 2 `str`.
:rtype: bool
"""
assert isinstance(u_string, str)
try:
u_string.encode('ascii')
return True
except UnicodeEncodeError:
return False
