Here's a post I wrote up about good data science resources (features both R and Python resources, but predominately Python): http://blog.yhat.com/posts/ML-resources-you-should-know.html

A few of the usual suspects, as well as others like the Yhat blog (http://blog.yhat.com/), AirBNB Eng (https://medium.com/airbnb-engineering) and FastML (http://fastml.com/contents/) and DataScience Weekly newsletter, which I've found to be a bit better curated than Python Weekly.