Good day.

Dear Team,

First allow me to thank for your job. 

Your tutorial is easy and helping alot in bulding one's knowledge on the subject.

I have expirienced some issue with examples that you have put in and would like to ask your assitance how to overcome it.

I'm trying to code in parallel to your tutorial to check/compare if i got it correctly. 

Recently import of SPY data is not working well returning following error

AuthenticationError: (Status 400) (Quandl Error QEAx01) We could not recognize your API key. Please check your API key and try again.

I have used the same code as in the Tutorial

quandl.ApiConfig.api_key = '_fgkxjSbt5389zGt4crC'

spy_table = quandl.get('BCIW/_SPXT')
amzn_table = quandl.get('WIKI/AMZN') 

Is there a free data which correspondes to the one used in tutorial?

Thanks in advance.