finance.fetch_historical_yahoo: Create directories leading up to cachename.

Previously, if cachename was specified, it would create the directories to
cachedir instead, resulting in OSError if the directories leading up to
cachename were not specified.

Author: mgiuca-google

lib/matplotlib/finance.py

@@ -184,7 +184,7 @@ def fetch_historical_yahoo(ticker, date1, date2, cachename=None,dividends=False)
         fh = open(cachename)
         verbose.report('Using cachefile %s for %s'%(cachename, ticker))
     else:
-        mkdirs(cachedir)
+        mkdirs(os.path.abspath(os.path.dirname(cachename)))
         urlfh = urlopen(url)
 
         fh = open(cachename, 'wb')