name : _internal_utils.py """ requests._internal_utils ~~~~~~~~~~~~~~ Provides utility functions that are consumed internally by Requests which depend on extremely few external helpers (such as compat) """ import re from .compat import builtin_str _VALID_HEADER_NAME_RE_BYTE = re.compile(rb"^[^:\s][^:\r\n]*$") _VALID_HEADER_NAME_RE_STR = re.compile(r"^[^:\s][^:\r\n]*$") _VALID_HEADER_VALUE_RE_BYTE = re.compile(rb"^\S[^\r\n]*$|^$") _VALID_HEADER_VALUE_RE_STR = re.compile(r"^\S[^\r\n]*$|^$") _HEADER_VALIDATORS_STR = (_VALID_HEADER_NAME_RE_STR, _VALID_HEADER_VALUE_RE_STR) _HEADER_VALIDATORS_BYTE = (_VALID_HEADER_NAME_RE_BYTE, _VALID_HEADER_VALUE_RE_BYTE) HEADER_VALIDATORS = { bytes: _HEADER_VALIDATORS_BYTE, str: _HEADER_VALIDATORS_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: 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