This is extension of this post by David Cerezo Sanchez where he posted the following useful Python libraries :

- SymPy, a Python library for symbolic mathematics
- Pattern, web mining module for Python
- NLTK, natural language processing with Python
- Scapy, interactive packet manipulation program
- Bitey and llvm-py, to import and modify LLVM bytecode

All of them extremely useful but there are some that I would like to add :

- scipy, for advanced math, signal processing, optimization and statistics
- NumPy, for linear algebra, Fourier transform, and random number capabilities
- matplotlib, for 2D plotting
- Twisted, to implement network protocol parsing and handling for TCP servers
- Python for iOS, not a library but very useful tool for using python on iOS devices