Python 3 Beginner's Reference Cheat Sheet by paul_benn

Assignment	=
Arithmetic	+, -, *, /, %
Comparison	>, >=, <, <=, ==, !=
Logical	not, and, or

s.coun­t(s­ubs­tring)	Count occurences
s.find­(su­bst­ring)	Index of first occurence
s.join­(se­quence)	Concat­enate sequence
s.spli­t([­del­imi­ter])	Split into list

l.appe­nd(e)	Add e
l.remo­ve(e)	Remove e
l.pop(e)	Remove and return e
l.count(e)	Count occurences
l.reve­rse()	Reverse l
l.sort()	Sort l

d.clear()	Clear d
d.get(k)	Return d[k]
d.keys()	Return keys in d
d.values()	Return values in d
d.items()	Return key-value pairs in d

f = open(path)	Open f
f.read()	Read f
f.read­line()	Read line from f
f.read­lines()	Return list of lines in f
f.write(s)	Write s to f
f.close()	Close f

int(), float(), str(), bool()...	Type casting
len(data)	Length
min(va­lues), max(va­lues)	Minimum / Maximum
pow(x,y, [z])	X to the power Y [mod Z]
range(­start, stop, [step])	Ordered list
input(), print()	Console Input/­Output
filter­(fu­nction, array)	Filter array
map(fu­nction, array)	Map function onto array
id(object)	Unique object ID
round(n, [x])	Round n [x decimal places]

if(cond): <co­de> else: <co­de>	If-else
if(cond1): <co­de> elif(c­ond1): <co­de> else: <co­de>	If-eli­f-else
for i in range(­[st­art], stop, [step]): <co­de>	For loop over range
for i in items: <co­de>	For loop over iterable
while(­con­dit­ion): <co­de>	While loop
break	Exit first enclosing loop
continue	Skip to next iteration

math, numpy, scipy	Math
matplotlib	Graph plotting
random	Random generators
datetime	Date and time
timeit	Perfor­mance
re	Regular expres­sions
os	OS intera­ction
sys	stdin, stdout, stderr, version
urllib	Internet access
zlib	Data compre­ssion

class Person:	Class definition
x = Person­(age, height)	Object creation
x.age	Field access
x.birt­hday()	Method access