The tickers used in pandas morningstar API

问题

Here is what I done for obtaining the price of the stock "TSLA" using the DataReader with morningstar API

import pandas_datareader.data as web
df = web.DataReader('TSLA', 'morningstar', start, end)

However, if I input a wrong ticker for the first parameter of the creator of DataReader, Python just keep running the line.

How to check whether a ticker is input correctly for the first parameter?

回答1:

When I ran your code with an invalid ticker symbol, I experienced the same problem with the Python Interpreter just hanging. I didn't find an entirely neat solution, but based on a somewhat related issue report I read on github (link here), I've come up with an answer that will stop the python interpreter from hanging if you enter an invalid ticker symbol.

The key seems to be setting the retry_count parameter of pandas_datareader.data.DataReader() equal to zero.

I have a fully reproducible snippet below:

import pandas_datareader
import datetime

start = datetime.datetime(2018, 5, 1)
end = datetime.datetime(2018, 5, 30)

def get_data(ticker):
    try:
        df = pandas_datareader.data.DataReader('%s' % (ticker), 'morningstar', start, end, retry_count=0)
        print(df.tail(5))
    except ValueError:
        print('Ticker Symbol %s is not available!' % (ticker))

get_data('TSLA') #valid Symbol
get_data('yyfy') #not a valid Symbol
get_data('AAPL') #valid Symbol
get_data('QQQQ') #not a valid Symbol

With Expected Output:

Symbol Date        Close     High     Low      Open   Volume
TSLA   2018-05-24  277.85  281.110  274.89  278.4000  4190598
       2018-05-25  278.85  279.640  275.61  277.6252  3875082
       2018-05-28  278.85  278.850  278.85  278.8500        0
       2018-05-29  283.76  286.500  276.15  278.5100  5666640
       2018-05-30  291.72  295.005  281.60  283.2900  7428352

Ticker Symbol yyfy is not available!

Symbol Date        Close    High     Low    Open    Volume
AAPL   2018-05-24  188.15  188.84  186.21  188.77  20330134
       2018-05-25  188.58  189.65  187.65  188.23  17460963
       2018-05-28  188.58  188.58  188.58  188.58         0
       2018-05-29  187.90  188.75  186.87  187.60  22514075
       2018-05-30  187.50  188.00  186.78  187.72  18430891

Ticker Symbol QQQQ is not available!

来源：https://stackoverflow.com/questions/50478715/the-tickers-used-in-pandas-morningstar-api

标签

python

pandas-datareader