Update request urllib3 (#464)

* requests: updated to version 2.27.1

* urllib3: updated to version 1.26.18

lib/requests/__init__.py

@@ -9,14 +9,14 @@
 Requests HTTP Library
 ~~~~~~~~~~~~~~~~~~~~~
 
-Requests is an HTTP library, written in Python, for human beings. Basic GET
-usage:
+Requests is an HTTP library, written in Python, for human beings.
+Basic GET usage:
 
    >>> import requests
    >>> r = requests.get('https://www.python.org')
    >>> r.status_code
    200
-   >>> 'Python is a programming language' in r.content
+   >>> b'Python is a programming language' in r.content
    True
 
 ... or POST:
@@ -27,26 +27,34 @@ usage:
    {
      ...
      "form": {
-       "key2": "value2",
-       "key1": "value1"
+       "key1": "value1",
+       "key2": "value2"
      },
      ...
    }
 
 The other HTTP methods are supported - see `requests.api`. Full documentation
-is at <http://python-requests.org>.
+is at <https://requests.readthedocs.io>.
 
 :copyright: (c) 2017 by Kenneth Reitz.
 :license: Apache 2.0, see LICENSE for more details.
 """
 
 import urllib3
-import chardet
 import warnings
 from .exceptions import RequestsDependencyWarning
 
+try:
+    from charset_normalizer import __version__ as charset_normalizer_version
+except ImportError:
+    charset_normalizer_version = None
 
-def check_compatibility(urllib3_version, chardet_version):
+try:
+    from chardet import __version__ as chardet_version
+except ImportError:
+    chardet_version = None
+
+def check_compatibility(urllib3_version, chardet_version, charset_normalizer_version):
     urllib3_version = urllib3_version.split('.')
     assert urllib3_version != ['dev']  # Verify urllib3 isn't installed from git.
 
@@ -57,19 +65,24 @@ def check_compatibility(urllib3_version, chardet_version):
     # Check urllib3 for compatibility.
     major, minor, patch = urllib3_version  # noqa: F811
     major, minor, patch = int(major), int(minor), int(patch)
-    # urllib3 >= 1.21.1, <= 1.25
+    # urllib3 >= 1.21.1, <= 1.26
     assert major == 1
     assert minor >= 21
-    assert minor <= 25
-
-    # Check chardet for compatibility.
-    major, minor, patch = chardet_version.split('.')[:3]
-    major, minor, patch = int(major), int(minor), int(patch)
-    # chardet >= 3.0.2, < 3.1.0
-    assert major == 3
-    assert minor < 1
-    assert patch >= 2
+    assert minor <= 26
 
+    # Check charset_normalizer for compatibility.
+    if chardet_version:
+        major, minor, patch = chardet_version.split('.')[:3]
+        major, minor, patch = int(major), int(minor), int(patch)
+        # chardet_version >= 3.0.2, < 5.0.0
+        assert (3, 0, 2) <= (major, minor, patch) < (5, 0, 0)
+    elif charset_normalizer_version:
+        major, minor, patch = charset_normalizer_version.split('.')[:3]
+        major, minor, patch = int(major), int(minor), int(patch)
+        # charset_normalizer >= 2.0.0 < 3.0.0
+        assert (2, 0, 0) <= (major, minor, patch) < (3, 0, 0)
+    else:
+        raise Exception("You need either charset_normalizer or chardet installed")
 
 def _check_cryptography(cryptography_version):
     # cryptography < 1.3.4
@@ -84,20 +97,28 @@ def _check_cryptography(cryptography_version):
 
 # Check imported dependencies for compatibility.
 try:
-    check_compatibility(urllib3.__version__, chardet.__version__)
+    check_compatibility(urllib3.__version__, chardet_version, charset_normalizer_version)
 except (AssertionError, ValueError):
-    warnings.warn("urllib3 ({}) or chardet ({}) doesn't match a supported "
-                  "version!".format(urllib3.__version__, chardet.__version__),
+    warnings.warn("urllib3 ({}) or chardet ({})/charset_normalizer ({}) doesn't match a supported "
+                  "version!".format(urllib3.__version__, chardet_version, charset_normalizer_version),
                   RequestsDependencyWarning)
 
-# Attempt to enable urllib3's SNI support, if possible
+# Attempt to enable urllib3's fallback for SNI support
+# if the standard library doesn't support SNI or the
+# 'ssl' library isn't available.
 try:
-    from urllib3.contrib import pyopenssl
-    pyopenssl.inject_into_urllib3()
+    try:
+        import ssl
+    except ImportError:
+        ssl = None
 
-    # Check cryptography version
-    from cryptography import __version__ as cryptography_version
-    _check_cryptography(cryptography_version)
+    if not getattr(ssl, "HAS_SNI", False):
+        from urllib3.contrib import pyopenssl
+        pyopenssl.inject_into_urllib3()
+
+        # Check cryptography version
+        from cryptography import __version__ as cryptography_version
+        _check_cryptography(cryptography_version)
 except ImportError:
     pass
 
@@ -118,7 +139,7 @@ from .status_codes import codes
 from .exceptions import (
     RequestException, Timeout, URLRequired,
     TooManyRedirects, HTTPError, ConnectionError,
-    FileModeWarning, ConnectTimeout, ReadTimeout
+    FileModeWarning, ConnectTimeout, ReadTimeout, JSONDecodeError
 )
 
 # Set default logging handler to avoid "No handler found" warnings.