[tedmiston]

The main reasons Python is so popular in science (ML and before) is:

1. It's easier to get started than Java, Go, etc.

2. It's faster to write/prototype. (The IPython REPL and Jupyter notebooks are awesome.)

3. The Python community is also very open source friendly and has significant momentum in third party packages like pandas, numpy, scipy, etc.

Check out some talks from past PyCons and you will see a very strong scientific presence more so than the other languages you mentioned.