Python 3 web crawler learning suggestions?

Title, the main python is only more familiar with the NumPy and scipy, matplotlib these three packages, are doing scientific research when in use. The recent impulse to write a few machine learning algorithms, and then want to go to the site to climb some things to play, because in the future may want to get it to their own unfinished automatic trading program, but also is a prototype, there is a long way to go.

But in the office of the afternoon, found that the web crawler is a big pit, the current understanding is scrapy is not suitable for python3, so I am just learning requests and beautifulsoup these two bags. Want to ask the web crawler this piece of experts, there is no recommended to see the tutorial or teaching, blog or something, really want to study in this piece carefully.

Thanks first!

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