What do you wish you'd known about when you started learning Python? [closed]

Answer 1

That a tuple of a single item must end with a comma, or it won't be interpreted as a tuple.

pprint() is very handy (yes, 2 p's)

reload() is useful when you're re-testing a module while making lots of rapid changes to a dependent module.

And learn as many common "idioms" as you can, otherwise you'll bang your head looking for a better way to do something, when the idiom really is regarded as the best way (e.g. ugly expressions like ' '.join(), or the answer to why there is no isInt(string) function.... the answer is you can just wrap the usage of a "possible" integer with a try: and then catch the exception if it's not a valid int. The solution works well, but it sounds like a terrible answer when you first encounter it, so you can waste a lot of time convincing yourself it really is a good approach.

Those are some things that wasted several hours of my time to determine that my first draft of some code which felt wrong, really was acceptable.

Readings from python.org:

http://wiki.python.org/moin/BeginnerErrorsWithPythonProgramming http://wiki.python.org/moin/PythonWarts

Answer 2

When I started with python, started out with main methods from the examples. This was because I didn't know better, after that I found this on how to create a better main method.

Answer 3

Pretty printing:

>>> print "%s world" %('hello')
hello world

%s for string

%d for integer

%f for float

%.xf for exactly x many decimal places of a float. If the float has lesser decimals that indicated, then 0s are added

Answer 4

I wish I'd known right off the bat how to code idiomatically in Python. You can pick up any language you like and start coding in it like it's C, Java, etc. but ideally you'll learn to code in "the spirit" of the language. Python is particularly relevant, as I think it has a definite style of its own.

While I found it a little later in my Python career than I would have liked, this excellent article wraps up many Python idioms and the little tricks that make it special. Several of the things people have mentioned in their answers so far are contained within: Code Like a Pythonista: Idiomatic Python.

Enjoy!

Answer 5

• using help() in the shell on any object, class or path
• you can run import code; code.interact(local=locals()) anywhere in your code and it will start a python shell at that exact point
• you can run python -i yourscript.py to start a shell at the end of yourscript.py

Answer 6

1. I wished I didn't know Java.
2. More functional programming. (see itertools module, list comprehension, map(), reduce() or filter())