update requests

lib/requests/compat.py

@@ -1,20 +1,34 @@
-# -*- coding: utf-8 -*-
-
 """
 requests.compat
 ~~~~~~~~~~~~~~~
 
-This module handles import compatibility issues between Python 2 and
-Python 3.
+This module previously handled import compatibility issues
+between Python 2 and Python 3. It remains for backwards
+compatibility until the next major version.
 """
 
-try:
-    import chardet
-except ImportError:
-    import charset_normalizer as chardet
-
+import importlib
 import sys
 
+# -------------------
+# Character Detection
+# -------------------
+
+
+def _resolve_char_detection():
+    """Find supported character detection libraries."""
+    chardet = None
+    for lib in ("chardet", "charset_normalizer"):
+        if chardet is None:
+            try:
+                chardet = importlib.import_module(lib)
+            except ImportError:
+                pass
+    return chardet
+
+
+chardet = _resolve_char_detection()
+
 # -------
 # Pythons
 # -------
@@ -23,59 +37,58 @@ import sys
 _ver = sys.version_info
 
 #: Python 2.x?
-is_py2 = (_ver[0] == 2)
+is_py2 = _ver[0] == 2
 
 #: Python 3.x?
-is_py3 = (_ver[0] == 3)
+is_py3 = _ver[0] == 3
 
+# json/simplejson module import resolution
 has_simplejson = False
 try:
     import simplejson as json
+
     has_simplejson = True
 except ImportError:
     import json
 
-# ---------
-# Specifics
-# ---------
+if has_simplejson:
+    from simplejson import JSONDecodeError
+else:
+    from json import JSONDecodeError
 
-if is_py2:
-    from urllib import (
-        quote, unquote, quote_plus, unquote_plus, urlencode, getproxies,
-        proxy_bypass, proxy_bypass_environment, getproxies_environment)
-    from urlparse import urlparse, urlunparse, urljoin, urlsplit, urldefrag
-    from urllib2 import parse_http_list
-    import cookielib
-    from Cookie import Morsel
-    from StringIO import StringIO
-    # Keep OrderedDict for backwards compatibility.
-    from collections import Callable, Mapping, MutableMapping, OrderedDict
+# Keep OrderedDict for backwards compatibility.
+from collections import OrderedDict
+from collections.abc import Callable, Mapping, MutableMapping
+from http import cookiejar as cookielib
+from http.cookies import Morsel
+from io import StringIO
 
-    builtin_str = str
-    bytes = str
-    str = unicode
-    basestring = basestring
-    numeric_types = (int, long, float)
-    integer_types = (int, long)
-    JSONDecodeError = ValueError
+# --------------
+# Legacy Imports
+# --------------
+from urllib.parse import (
+    quote,
+    quote_plus,
+    unquote,
+    unquote_plus,
+    urldefrag,
+    urlencode,
+    urljoin,
+    urlparse,
+    urlsplit,
+    urlunparse,
+)
+from urllib.request import (
+    getproxies,
+    getproxies_environment,
+    parse_http_list,
+    proxy_bypass,
+    proxy_bypass_environment,
+)
 
-elif is_py3:
-    from urllib.parse import urlparse, urlunparse, urljoin, urlsplit, urlencode, quote, unquote, quote_plus, unquote_plus, urldefrag
-    from urllib.request import parse_http_list, getproxies, proxy_bypass, proxy_bypass_environment, getproxies_environment
-    from http import cookiejar as cookielib
-    from http.cookies import Morsel
-    from io import StringIO
-    # Keep OrderedDict for backwards compatibility.
-    from collections import OrderedDict
-    from collections.abc import Callable, Mapping, MutableMapping
-    if has_simplejson:
-        from simplejson import JSONDecodeError
-    else:
-        from json import JSONDecodeError
-
-    builtin_str = str
-    str = str
-    bytes = bytes
-    basestring = (str, bytes)
-    numeric_types = (int, float)
-    integer_types = (int,)
+builtin_str = str
+str = str
+bytes = bytes
+basestring = (str, bytes)
+numeric_types = (int, float)
+integer_types = (int,)