Web:
Requests: https://pypi.org/project/requests/
Django: https://pypi.org/project/Django/
Flask: https://pypi.org/project/Flask/
Twisted: https://twistedmatrix.com/trac/
BeautifulSoup: https://pypi.org/project/beautifulsoup4/
Selenium: https://selenium-python.readthedocs.io/
Data science:
Numpy: https://numpy.org/
Pandas: https://pandas.pydata.org/
Matplotlib: https://matplotlib.org/
Nltk: https://www.nltk.org/
Opencv: https://selenium-python.readthedocs.io/
Machine Learning:
Tensorflow: https://www.tensorflow.org/
Keras: https://keras.io/
PyTorch: https://pytorch.org/
Sci-kit Learn: https://scikit-learn.org/stable/
GUI:
Kivy: https://kivy.org/#home
PyQt5: https://pypi.org/project/PyQt5/
Tkinter: https://wiki.python.org/moin/TkInter
Games:
Pygame: https://www.pygame.org/docs/