Merge pull request #1930 from ranaroussi/fix/session-switching

Fix switching session from/to requests_cache

yfinance/data.py

@@ -60,24 +60,8 @@ class YfData(metaclass=SingletonMeta):
         'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.95 Safari/537.36'}
 
     def __init__(self, session=None):
-        self._session = session or requests.Session()
-
-        try:
-            self._session.cache
-        except AttributeError:
-            # Not caching
-            self._session_is_caching = False
-        else:
-            # Is caching. This is annoying.
-            # Can't simply use a non-caching session to fetch cookie & crumb,
-            # because then the caching-session won't have cookie.
-            self._session_is_caching = True
-            from requests_cache import DO_NOT_CACHE
-            self._expire_after = DO_NOT_CACHE
         self._crumb = None
         self._cookie = None
-        if self._session_is_caching and self._cookie is None:
-            utils.print_once("WARNING: cookie & crumb does not work well with requests_cache. Am experimenting with 'expire_after=DO_NOT_CACHE', but you need to help stress-test.")
 
         # Default to using 'basic' strategy
         self._cookie_strategy = 'basic'
@@ -86,12 +70,27 @@ def __init__(self, session=None):
 
         self._cookie_lock = threading.Lock()
 
+        self._set_session(session or requests.Session())
+
     def _set_session(self, session):
         if session is None:
             return
         with self._cookie_lock:
             self._session = session
 
+        try:
+            self._session.cache
+        except AttributeError:
+            # Not caching
+            self._session_is_caching = False
+        else:
+            # Is caching. This is annoying.
+            # Can't simply use a non-caching session to fetch cookie & crumb,
+            # because then the caching-session won't have cookie.
+            self._session_is_caching = True
+            from requests_cache import DO_NOT_CACHE
+            self._expire_after = DO_NOT_CACHE
+
     def _set_cookie_strategy(self, strategy, have_lock=False):
         if strategy == self._cookie_strategy:
             return