update requests

lib/requests/_internal_utils.py

@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 """
 requests._internal_utils
 ~~~~~~~~~~~~~~
@@ -7,11 +5,24 @@ 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 is_py2, builtin_str, str
+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'):
+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.
@@ -19,10 +30,7 @@ def to_native_string(string, encoding='ascii'):
     if isinstance(string, builtin_str):
         out = string
     else:
-        if is_py2:
-            out = string.encode(encoding)
-        else:
-            out = string.decode(encoding)
+        out = string.decode(encoding)
 
     return out
 
@@ -36,7 +44,7 @@ def unicode_is_ascii(u_string):
     """
     assert isinstance(u_string, str)
     try:
-        u_string.encode('ascii')
+        u_string.encode("ascii")
         return True
     except UnicodeEncodeError:
         return False