As a quick (and hopefully painless) introduction to the whole topic, have a look at:
If you want to know about the basics of Python and nothing else (no numeric Python, no plotting, no signal processing, just the very basics), that's for you:
More topics:
Warning: The following topics are very much work in progress!
TODO: more topics ...
There are quite a few blog posts and other resources available, here are a few links, use your favorite search engine to find more.
http://scipy-lectures.github.io/
https://github.com/jrjohansson/scientific-python-lectures
http://pig-in-the-python.blogspot.de/
http://www.southampton.ac.uk/~feeg1001/index.html
Computational Methods for Psychology and Neuroscience: http://memory.osu.edu/classes/python/index.html
https://github.com/IanHawke/maths-with-python
http://www.southampton.ac.uk/~fangohr/training/python/index.html
PHY 546: Python for Scientific Computing: http://bender.astro.sunysb.edu/classes/python-science/
https://www.dataquest.io/blog/numpy-tutorial-python/
http://blancosilva.github.io/post/2014/10/28/Computational-Geometry-in-Python.html
http://matthew-brett.github.io/teaching/
http://jakevdp.github.io/blog/2017/03/03/reproducible-data-analysis-in-jupyter/
Python Data Science Handbook: full text in Jupyter Notebooks
https://github.com/jakevdp/PythonDataScienceHandbook
Machine Learning for Artists: https://ml4a.github.io/index/, https://github.com/ml4a/ml4a-guides
Notes on Artificial Intelligence: https://frnsys.com/ai_notes/
IPython Cookbook, Second Edition (2018): http://ipython-books.github.io/
Learning Python for Social Scientists: https://nealcaren.github.io/python-tutorials/
https://calculus-notes.readthedocs.io/
Ten Simple Rules for Reproducible Research in Jupyter Notebooks:
https://arxiv.org/abs/1810.08055
https://github.com/jupyter-guide/ten-rules-jupyter
Guide for Reproducible Research and Data Science in Jupyter Notebooks:
https://github.com/jupyter-guide/jupyter-guide
http://cscircles.cemc.uwaterloo.ca/
http://docs.python.org/3/tutorial/
http://learnpythonthehardway.org/book/
http://getpython3.com/diveintopython3/index.html
http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html
http://lignos.org/py_antipatterns/
http://www.digilentinc.com/Classroom/IntroProgramming1/
https://github.com/JonasSC/PythonistManifesto
https://github.com/rasbt/python_reference
http://www.greenteapress.com/thinkpython/
Programming with Python (MATH20622): http://www.maths.manchester.ac.uk/~vsego/teaching.php
https://github.com/justmarkham/python-reference
pytudes: Python programs for perfecting programming skills
https://github.com/norvig/pytudes
https://github.com/arokem/python-matlab-bridge
http://wiki.scipy.org/NumPy_for_Matlab_Users
http://bastibe.de/2013-01-20-a-python-primer-for-matlab-users.html