Python Cheat Sheet

Python 구문 목록

출처 : List Of Syntax Used In Python!

Python

Language Category: Object Oriented, Dynamically typed, Has anonymous functions
Various
indentation	block (grouping statements, especially when statements are not expressions)
\	breaking lines (useful when end-of-line and/or indentation has a special meaning)
#	commenting (until end of line)
< > <= >=	comparison
min / max	comparison (min / max (binary or more))
cmp	comparison (returns 3 values (i.e. inferior, equal or superior))
class X: """... """ def x(): """... """	documentation comment
Err:510	equality / inequality (deep)
Err:510	equality / inequality (deep)
is / is not	equality / inequality (shallow)
gc.collect()	force garbage collection
( ... )	grouping expressions
__file__	information about the current line and file
eval	runtime evaluation
exec	runtime evaluation
case-sensitive	tokens (case-sensitivity (keywords, variable identifiers...))
[_a-zA-Z][_a-zA-Z0-9]*	tokens (variable identifier regexp)
CamelCase for classes, underscores for methods	tokens (what is the standard way for scrunching together multiple words)
=	variable assignment or declaration (both)
global v1, v2	variable assignment or declaration (declaration)
Functions
functools.partial(f, a)	partial application (in the examples below, a normal call is "f(a,b)") (give the first argument)
lambda a, b: ...	anonymous function
f(a,b,...)	function call
f()	function call (with no parameter)
__getattr__	function called when a function is not defined (in dynamic languages)
def f(para1, para2, ...): ...	function definition
return	function return value (breaks the control flow)
inspect.stack()[1]	runtime inspecting the caller information
Control Flow
continue / break	breaking control flow (continue / break)
return	breaking control flow (returning a value)
try: a except exn: ...	exception (catching)
finally	exception (cleanup: code executed before leaving)
raise	exception (throwing)
if c: ...	if_then
b1 if c else b2	if_then_else
if c:  b1  elif c2: b2  else:  b3	if_then_else
for i in xrange(10, 0, -1)	loop (for each value in a numeric range, 1 decrement)
for i in xrange(1, 11)	loop (for each value in a numeric range, 1 increment (see also the entries about ranges))
for i in xrange(1, 11, 2)	loop (for each value in a numeric range, free increment)
while c: ...	loop (while condition do something)
;	sequence
end-of-line	sequence
Types
t(e)	cast (computed conversion (calls an internal or a user-defined function))
n = t	declaration
Object Oriented & Reflexivity
super(Class, self).meth(args)	accessing parent method
class	class declaration
first parameter	current instance
__class__	get the type/class corresponding to an object/instance/value
hasattr(obj, "meth")	has the method
class child(parent):	inheritance
del, __del__	manually call an object's destructor
object.method(para)	method invocation
object.method()	method invocation (with no parameter)
dir	methods available
copy.copy(o)	object cloning
class_name(...)	object creation
isinstance	testing class membership
Package, Module
automatically done based on the file name	declare
__all__ = [ ... ]	declare (selective export)
from p import *	import (everything into current namespace)
import p	import (package (ie. load the package))
from p import name1, name2, ...	import (selectively)
0	package scope
Strings
s[n]	accessing n-th character
chr	ascii to character
ord	character to ascii
str, `e`, repr	convert something to a string (see also string interpolation)
*	duplicate n times
s[n:m+1]	extract a substring
index	locate a substring
find	locate a substring
rindex	locate a substring (starting at the end)
rfind	locate a substring (starting at the end)
'''...''', """..."""	multi-line
pickle.dump	serialize (marshalling)
print	simple print (on any objects)
print e,	simple print (on any objects)
%	sprintf-like
0	string concatenation
Err:510	string equality & inequality
Err:510	string equality & inequality
len	string size
"\n"	strings (end-of-line (without writing the real CR or LF character))
"... %(v)s ..." % vars()	strings (with interpolation of variables)
'...'	strings (with no interpolation of variables)
"..."	strings (with no interpolation of variables)
'''...'''	strings (with no interpolation of variables)
"""..."""	strings (with no interpolation of variables)
str	type name
pickle.load	unserialize (un-marshalling)
upper / lower	upper / lower case character
upper / lower / capitalize	uppercase / lowercase / capitalized string
Booleans
False	false value
None	false value
0	false value
""	false value
()	false value
[]	false value
{}	false value
not	logical not
or / and	logical or / and (short circuit)
True	true value
anything not false	true value
bool	type name
Bags and Lists
zip(*l)	2 lists from a list of couples
a.insert(i, e)	adding an element at index (side-effect)
append	adding an element at the end (side-effect)
l[1:]	all but the first element
reduce	f(... f(f(init, e1), e2) ..., en)
index	find an element
for v in l: ...	for each element do something
pop	get the last element and remove it
in	is an element in the list
any	is the predicate true for an element
all	is the predicate true for every element
enumerate(l)	iterate with index
s.join(l)	join a list of strings in a string using a glue string
filter	keep elements (matching)
[ x for x in l if p(x) ]	keep elements (matching)
a[-1]	last element
0	list concatenation
[ a, b, c ]	list constructor
zip	list of couples from 2 lists
list	list out of a bag
len	list size
a[i]	list/array indexing
set	remove duplicates
reverse	reverse
reversed	reverse
l[::-1]	reverse
min / max	smallest / biggest element
sort	sort
sorted	sort
map	transform a list (or bag) in another one
[ f(x) for x in l ]	transform a list (or bag) in another one
map	transform two lists in parallel
list	type name
Various Data Types
a,	computable tuple (these are a kind of immutable lists playing a special role in parameter passing) (1-uple)
tuple([a])	computable tuple (these are a kind of immutable lists playing a special role in parameter passing) (1-uple)
()	computable tuple (these are a kind of immutable lists playing a special role in parameter passing) (empty tuple)
*t	computable tuple (these are a kind of immutable lists playing a special role in parameter passing) (using a tuple for a function call)
h.get(k, returned_value_when_k_unfound)	dictionary (access: read)
h[k]	dictionary (access: read/write)
{ a: b, c: d }	dictionary (constructor)
has_key	dictionary (has the key ?)
k in h	dictionary (has the key ?)
k not in h	dictionary (has the key ?)
keys	dictionary (list of keys)
values	dictionary (list of values)
update	dictionary (merge)
del h[k]	dictionary (remove by key)
dict	dictionary (type name)
or	optional value (null coalescing)
None	optional value (null value)
v	optional value (value)
range	range (inclusive .. exclusive)
0	record (selector)
a, b, c	tuple constructor
tuple	tuple type
Mathematics
+ / - / * / /	addition / subtraction / multiplication / division
& / | / ^	bitwise operators (and / or / xor)
~	bitwise operators (bitwise inversion)
<< / >>	bitwise operators (left shift / right shift / unsigned right shift)
divmod	euclidian division (both quotient and modulo)
**	exponentiation (power)
pow	exponentiation (power)
log10	logarithm (base 10)
log(val, 2)	logarithm (base 2)
log	logarithm (base e)
%	modulo (modulo of -3 / 2 is 1)
-0	negation
1000., 1E3	numbers syntax (floating point)
07, 0xf	numbers syntax (integers in base 2, octal and hexadecimal)
1000	numbers syntax (integers)
mathematical	operator priorities and associativities (addition vs multiplication)
mathematical	operator priorities and associativities (exponentiation vs negation (is -3^2 equal to 9 or -9))
random	random (random number)
random.seed	random (seed the pseudo random generator)
sqrt / exp / abs	square root / e-exponential / absolute value
sin / cos / tan	trigonometry (basic)
asin / acos / atan	trigonometry (inverse)
int / round / floor / ceil	truncate / round / floor / ceil
float, decimal.Decimal	type name (floating point)
int, long	type name (integers)
Threads
OtherThread.join()	Joining Another Thread (Suspending a thread until another thread completes)
class class_name(threading.Thread) {[override run method] }	thread definition