Comprehensive Python Cheatsheet (2018)

I like the basic script template that the author provides. However, when I start development of new code I always use a script that starts off with traceback and pdb, something like this: #!/usr/bin/env python import traceback import pdb import sys def main(): # some WIP code that maybe raises an exception raise BaseException("oh no, exception!") return 0 if __name__ == "__main__": try: ret = main() except: traceback.print_exc() pdb.post_mortem() sys.exit(ret) This means that whenever an uncaught exception gets…

Previous discussion: https://news.ycombinator.com/item?id=29679788 (243 points | Dec 25, 2021 | 57 comments) See also: * Python Crash Course cheatsheet: https://ehmatthes.github.io/pcc_3e/cheat_sheets/ * Scientific Python cheatsheet: https://ipgp.github.io/scientific_python_cheat_sheet/ * Common beginner errors: https://pythonforbiologists.com/29-common-beginner-errors-on... * Python regular expression cheatsheet: https://learnbyexample.github.io/python-regex-cheatsheet/ — my blog post, includes examples as well

I'm surprised to see mutable default values not mentioned. It's bitten me more than once to discover that: def f(xs = []): xs.append(5) return xs print(f()) print(f()) will print: [5] [5,5] and I love python despite this horrendous decision, but it should be mentioned more often in beginner resources. edit: thanks for the downvote? I've answered on the order of dozens of questions about this very mechanic on SO, via IRC, and more... it's a well-known confusing factor

Source: https://www.cs.princeton.edu/courses/archive/spring19/cos333...