Python

Pros:

• very fast as a scripting language, just write code and run it
• there is a library for everything
• still fast for DS / ML since the underlying libaries are on Cython.

Cons:

• type hints are awkward
• python 2 vs 3. python 2 sunsets on 1 jan 2020. Lots of projects have yet to migrate

GIL:

• Global interpreter lock
• Python uses reference counting for GC
• GIL used to prevent race conditions in ref counting.
• only a problem in CPython?

References

1. RealPython GIL: https://realpython.com/python-gil/
2. https://rushter.com/blog/python-garbage-collector/