Introducing Python, 2nd Edition

Appendix E. Cheat Sheets

I find myself looking up certain things a little too often. Here are some tables that I hope you’ll find useful.

Operator Precedence

This table is a remix of the official documentation on precedence in Python 3, with the highest precedence operators at the top.

Operator	Description and examples
[v, …], {v1, …}, {k1:v1, …}, (…)	List/set/dict/generator creation or comprehension, parenthesized expression
seq[n], seq[n:m], func(args…), obj.attr	Index, slice, function call, attribute reference
**	Exponentiation
+n, –n, ~n	Positive, negative, bitwise not
*, /, //, %	Multiplication, float division, int division, remainder
+, -	Addition, subtraction
<<, >>	Bitwise left, right shifts
&	Bitwise and
|	Bitwise or
in, not in, is, is not, <, <=, >, >=, !=, ==	Membership and equality tests
not x	Boolean (logical) not
and	Boolean and
or	Boolean or
if … else	Conditional expression
lambda …	lambda expression

String Methods

Python offers both string methods (can be used with any str object) and a string module with some useful definitions. Let’s use these test variables:

>>> s = "OH, my paws and whiskers!"
>>> t = "I'm late!"

In the following examples, the Python shell prints the result of the method call, but the original variables s and t are not changed.

Change Case

>>> s.capitalize()
'Oh, my paws and whiskers!'
>>> s.lower()
'oh, my paws and whiskers!'
>>> s.swapcase()
'oh, MY PAWS AND WHISKERS!'
>>> s.title()
'Oh, My Paws And ...