I don't have any code examples, but I recall:

- a lot of things I did in perl ended up using regular expressions

- in comparison python use of regular expressions is not first-class so many problems would use string functions instead. (although r'<expr>' was less ambiguous wrt quoting rules)

- in perl path manipulation would use regular expressions

- in python I embraced os.path

- I would use oo in python, but rarely in perl

- argparse