KEYWORDS

Keyword Description 	Example
and 	Logical and. 	True and False == False
as 	Part of the with-as statement. 	with X as Y: pass
assert 	Assert (ensure) that something is true. 	assert False, "Error!"
break 	Stop this loop right now. 	while True: break
class 	Define a class. 	class Person(object)
continue 	Don't process more of the loop, do it again. 	while True: continue
def 	Define a function. 	def X(): pass
del 	Delete from dictionary. 	del X[Y]
elif 	Else if condition. 	if: X; elif: Y; else: J
else 	Else condition. 	if: X; elif: Y; else: J
except 	If an exception happens, do this. 	except ValueError, e: print e
exec 	Run a string as Python. 	exec 'print "hello"'
finally 	Exceptions or not, finally do this no matter what. 	finally: pass
for 	Loop over a collection of things. 	for X in Y: pass
from 	Importing specific parts of a module. 	from x import Y
global 	Declare that you want a global variable. 	global X
if 	If condition. 	if: X; elif: Y; else: J
import 	Import a module into this one to use. 	import os
in 	Part of for-loops. Also a test of X in Y. 	for X in Y: pass also 1 in [1] == True
is 	Like == to test equality. 	1 is 1 == True
lambda 	Create a short anonymous function. 	s = lambda y: y ** y; s(3)
not 	Logical not. 	not True == False
or 	Logical or. 	True or False == True
pass 	This block is empty. 	def empty(): pass
print 	Print this string. 	print 'this string'
raise 	Raise an exception when things go wrong. 	raise ValueError("No")
return 	Exit the function with a return value. 	def X(): return Y
try 	Try this block, and if exception, go to except. 	try: pass
while 	While loop. 	while X: pass
with 	With an expression as a variable do. 	with X as Y: pass
yield 	Pause here and return to caller. 	def X(): yield Y; X().next()


DATA TYPES

For data types, write out what makes up each one. For example, with strings write out how you create a string. For numbers write out a few numbers.
Type 	Description 	Example
True 	True boolean value. 	True or False == True
False 	False boolean value. 	False and True == False
None 	Represents "nothing" or "no value". 	x = None
strings 	Stores textual information. 	x = "hello"
numbers 	Stores integers. 	i = 100
floats 	Stores decimals. 	i = 10.389
lists 	Stores a list of things. 	j = [1,2,3,4]
dicts 	Stores a key=value mapping of things. 	e = {'x': 1, 'y': 2}




STRING ESCAPE SEQUENCES

For string escape sequences, use them in strings to make sure they do what you think they do.
Escape 	Description
\\ 	Backslash
\' 	Single-quote
\" 	Double-quote
\a 	Bell
\b 	Backspace
\f 	Formfeed
\n 	Newline
\r 	Carriage
\t 	Tab
\v 	Vertical tab



STRING FORMATS

Same thing for string formats: use them in some strings to know what they do.
Escape 	Description 	Example
%d 	Decimal integers (not floating point). 	"%d" % 45 == '45'
%i 	Same as %d. 	"%i" % 45 == '45'
%o 	Octal number. 	"%o" % 1000 == '1750'
%u 	Unsigned decimal. 	"%u" % -1000 == '-1000'
%x 	Hexadecimal lowercase. 	"%x" % 1000 == '3e8'
%X 	Hexadecimal uppercase. 	"%X" % 1000 == '3E8'
%e 	Exponential notation, lowercase 'e'. 	"%e" % 1000 == '1.000000e+03'
%E 	Exponential notation, uppercase 'E'. 	"%E" % 1000 == '1.000000E+03'
%f 	Floating point real number. 	"%f" % 10.34 == '10.340000'
%F 	Same as %f. 	"%F" % 10.34 == '10.340000'
%g 	Either %f or %e, whichever is shorter. 	"%g" % 10.34 == '10.34'
%G 	Same as %g but uppercase. 	"%G" % 10.34 == '10.34'
%c 	Character format. 	"%c" % 34 == '"'
%r 	Repr format (debugging format). 	"%r" % int == "<type 'int'>"
%s 	String format. 	"%s there" % 'hi' == 'hi there'
%% 	A percent sign. 	"%g%%" % 10.34 == '10.34%'




OPERATORS


Operator 	Description 	Example
+ 	Addition 	2 + 4 == 6
- 	Subtraction 	2 - 4 == -2
* 	Multiplication 	2 * 4 == 8
** 	Power of 	2 ** 4 == 16
/ 	Division 	2 / 4.0 == 0.5
// 	Floor division 	2 // 4.0 == 0.0
% 	String interpolate or modulus 	2 % 4 == 2
< 	Less than 	4 < 4 == False
> 	Greater than 	4 > 4 == False
<= 	Less than equal 	4 <= 4 == True
>= 	Greater than equal 	4 >= 4 == True
== 	Equal 	4 == 5 == False
!= 	Not equal 	4 != 5 == True
<> 	Not equal 	4 <> 5 == True
( ) 	Parenthesis 	len('hi') == 2
[ ] 	List brackets 	[1,3,4]
{ } 	Dict curly braces 	{'x': 5, 'y': 10}
@ 	At (decorators) 	@classmethod
, 	Comma 	range(0, 10)
: 	Colon 	def X():
. 	Dot 	self.x = 10
= 	Assign equal 	x = 10
; 	semi-colon 	print "hi"; print "there"
+= 	Add and assign 	x = 1; x += 2
-= 	Subtract and assign 	x = 1; x -= 2
*= 	Multiply and assign 	x = 1; x *= 2
/= 	Divide and assign 	x = 1; x /= 2
//= 	Floor divide and assign 	x = 1; x //= 2
%= 	Modulus assign 	x = 1; x %= 2
**= 	Power assign 	x = 1; x **= 2