avoid monkey patching requests.Session Fixes #301 (#302)

Author: graingert

docs/source/whatsnew/v0.5.0.txt

@@ -22,3 +22,4 @@ Bug Fixes
 - Handle commas in large price quotes (:issue:`345`)
 - Test suite fixes for test_get_options_data (:issue:`352`)
 - Test suite fixes for test_wdi_download (:issue:`350`)
+- avoid monkey patching requests.Session (:issue:`301`)

pandas_datareader/_utils.py

@@ -1,12 +1,10 @@
 import datetime as dt
-from pandas import to_datetime
-from requests_file import FileAdapter
-from pandas_datareader.compat import is_number
 
 import requests
-import requests_ftp
-
-requests_ftp.monkeypatch_session()
+from pandas import to_datetime
+from pandas_datareader.compat import is_number
+from requests_file import FileAdapter
+from requests_ftp import FTPAdapter
 
 
 class SymbolWarning(UserWarning):
@@ -43,5 +41,6 @@ def _init_session(session, retry_count=3):
     if session is None:
         session = requests.Session()
         session.mount('file://', FileAdapter())
+        session.mount('ftp://', FTPAdapter())
         # do not set requests max_retries here to support arbitrary pause
     return session

pandas_datareader/base.py

@@ -13,9 +13,6 @@
 from pandas_datareader._utils import (RemoteDataError, SymbolWarning,
                                       _sanitize_dates, _init_session)
 
-import requests_ftp
-requests_ftp.monkeypatch_session()
-
 
 class _BaseReader(object):
 

pandas_datareader/tests/test_base.py

@@ -1,8 +1,13 @@
 import pytest
+import requests
+
 import pandas_datareader.base as base
 
 
 class TestBaseReader(object):
+    def test_requests_not_monkey_patched(self):
+        assert not hasattr(requests.Session(), 'stor')
+
     def test_valid_retry_count(self):
         with pytest.raises(ValueError):
             base._BaseReader([], retry_count='stuff')