I am working my way through Wes McKinney's book Python For Data Analysis and on page 139 under Correlation and Covariance, I am getting an error when I try to run his code to obtain data from Yahoo! Finance.

Here is what I am running:

#CORRELATION AND COVARIANCE
import pandas.io.data as weball_data = {}
for ticker in ['AAPL', 'IBM', 'MSFT', 'GOOG']:all_data[ticker] = web.get_data_yahoo(ticker, '1/1/2003', '1/1/2013')price = DataFrame({tic: data['Adj Close']for tic, data in all_data.iteritems()})
volume = DataFrame({tic: data['Volume']for tic, data in all_data.iteritems()})

Here is the error I am getting:

Traceback (most recent call last):File "<stdin>", line 2, in <module>File "C:\Users\eMachine\WinPython-64bit-2.7.5.3\python-2.7.5.amd64\lib\site-packages\pandas\io\data.py", line 390, in get_data_yahooadjust_price, ret_index, chunksize, 'yahoo', name)File "C:\Users\eMachine\WinPython-64bit-2.7.5.3\python-2.7.5.amd64\lib\site-packages\pandas\io\data.py", line 336, in _get_data_fromhist_data = src_fn(symbols, start, end, retry_count, pause)File "C:\Users\eMachine\WinPython-64bit-2.7.5.3\python-2.7.5.amd64\lib\site-packages\pandas\io\data.py", line 190, in _get_hist_yahooreturn _retry_read_url(url, retry_count, pause, 'Yahoo!')File "C:\Users\eMachine\WinPython-64bit-2.7.5.3\python-2.7.5.amd64\lib\site-packages\pandas\io\data.py", line 169, in _retry_read_url"return a 200 for url %r" % (retry_count, name, url))
IOError: after 3 tries, Yahoo! did not return a 200 for url 'http://ichart.yahoo.com/table.csv?s=GOOG&a=0&b=1&c=2000&d=0&e=1&f=2010&g=d&ignore=.csv'
>>> ... >>> >>> ... >>> 

Any idea on what the problem is?

As Karl pointed out, the ticker had changed meaning Yahoo returns a 'page not found'.

When polling data from the web, it is a good idea to wrap the call in a try except

all_data = {}
for ticker in ['AAPL', 'IBM', 'MSFT', 'GOOG']:try:all_data[ticker] = web.get_data_yahoo(ticker, '1/1/2003', '1/1/2013')price = DataFrame({tic: data['Adj Close']for tic, data in all_data.iteritems()})volume = DataFrame({tic: data['Volume']for tic, data in all_data.iteritems()})except:print "Cant find ", ticker