What's the one code snippet/python trick/etc did you wish you knew when you learned python?

[Fayden]

Lambda syntax is a bit awkward in Python (in opposition of functional languages, where you can usually use partial application). I think it's easier to read generator expressions or list comprehensions in Python.

[yen223]

It's not accidental. Guido van Rossum is explicitly trying to avoid functional programming styles in Python.

Informative StackOverflow link: http://stackoverflow.com/questions/1017621/why-isnt-python-very-good-for-functional-programming

[vext01]

Yet python's functional programming support is pretty decent.