It’s literally Python, and if you’re writing sane/correct Python, you should hardly notice (things will work a little better, documentation will be more complete and actually accurate, etc). You can even do many of the same bizarre things that shitty Python programmers do without static typing, such as return differently types data based on the value of an input parameter. Someone passes in the string “asdf” so we’ll return an int, but if they pass “xyzfoo” we return a datetime. Next thing you know you’ve built matplotlib.