supplimental fix to pandas-datareader

gistfile1.txt

# supplimental fix to pandas-datareader-'0.4.1' (not yet pulled proposal)
#
#
#$ git clone https://github.com/rgkimball/pandas-datareader
#$ cd pandas-datareader
#$ git checkout fix-yahoo
#$ pip install -e .

def fetch_yahoo(ticker):
   NUM_RETRY = 5
   def is_convertible(x):
       return x != '' and x != 'null'
   def to_float(x):
       return float(x) if is_convertible(x) else np.nan
   def to_int(x):
       return int(x) if is_convertible(x) else np.nan
   def fetch(ticker):
       i = 0
       while True:
           try:
               return data.DataReader(ticker, 'yahoo')
           except:
               i += 1
               if i > NUM_RETRY:
                   raise Exception('could not get data from Yahoo Finance.')
   df = fetch(ticker)
   for c in df.columns:
       df[c] = df[c].apply(to_float if c != 'Volume' else to_int)
   return df