Support URL mirrors in the Pooch class

[dstansby]

Description of the desired feature:
It would be great to support data mirrors, ie. having values for base_url where the second, third etc. values can be used if the first URL isn't available.

Are you willing to help implement and maintain this feature?

Possibly

[leouieda]

Hi @dstansby thanks for suggesting this! I can see why this would be a nice feature to have.

One way to implement this would be allow base_url to take a list/tuple/set and then put this part of pooch.Pooch.fetch in a for loop with try: ... except:... blocks:

pooch/pooch/core.py

Line 587 in da2d93c

stream_download(

I don't have a lot of time to implement this right now but would gladly review (or ask someone else to review) if you're willing to give this a try.

[leouieda]

This would also be restricted to the Pooch class, at least for now. We can think about adding it to retrieve later is there is a desire.