Python
built in function:
abs():
Returns the absolute value of a number
Ex:
x
= abs(-7.25)
print(x)
7.25
all():Returns True if all items in an iterable
object are true
mylist
= [True, True, True]
x
= all(mylist)
print(x)
mylist
= [0, True, True]
y
= all(mylist)
print(y)
false
any() Returns True if any item in an iterable
object is true
mylist
= [False, True, False]
x
= any(mylist)
print(x)
True
ascii() Returns a readable version of an object.
Replaces none-ascii characters with escape character
x
= ascii("My name is Ståle")
print(x)
'My
name is St\xe5le'
bin() Returns the binary version of a number
x
= bin(36)
print(x)
0b100100
bool() Returns the boolean value of the specified
object
x
= bool(1)
print(x)
y
= bool(0)
print(y)
y
= bool('a')
print(y)
True
False
True
bytearray() Returns an array of bytes
x
= bytearray(4)
print(x)
bytearray(b'\x00\x00\x00\x00')
bytes() Returns a bytes object
x
= bytes(4)
print(x)
b'\x00\x00\x00\x00'
callable() Returns True if the specified object is
callable, otherwise False
def
x():
a = 5
print(callable(x))
true
chr() Returns a character from the specified
Unicode code.
x
= chr(97)
print(x)
a
compile() Returns the specified source as an object,
ready to be executed
x
= compile('print(55)', 'test', 'eval')
exec(x)
x
= compile('print(55)\nprint(88)', 'test', 'exec')
exec(x)
55
55
88
complex()
Returns a complex number
x
= complex(3, 5)
print(x)
(3+5j)
delattr() Deletes the specified attribute (property or
method) from the specified object
class
Person:
name = "John"
age = 36
country = "Norway"
delattr(Person,
'age')
dict() Returns a dictionary (Array)
x
= dict(name = "John", age = 36, country = "Norway")
print(x)
{'name':
'John', 'age': 36, 'country': 'Norway'}
dir() Returns a list of the specified object's
properties and methods
class
Person:
name = "John"
age = 36
country = "Norway"
print(dir(Person))
['__class__',
'__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__',
'__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__',
'__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__',
'__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__',
'age', 'country', 'name']
divmod() Returns the quotient and the remainder when
argument1 is divided by argument2
x
= divmod(5, 2)
print(x)
(2,
1)
enumerate() Takes a collection (e.g. a tuple) and
returns it as an enumerate object
x
= ('apple', 'banana', 'cherry')
y
= enumerate(x)
print(x)
('apple',
'banana', 'cherry')
eval() Evaluates and executes an expression
x
= 'print(55)'
eval(x)
55
exec() Executes the specified code (or object)
x
= 'name = "John"\nprint(name)'
exec(x)
John
filter() Use a filter function to exclude items in an
iterable object
ages
= [5, 12, 17, 18, 24, 32]
def
myFunc(x):
if x < 18:
return False
else:
return True
adults
= filter(myFunc, ages)
for
x in adults:
print(x)
output:
18
24
32
float()
Returns a floating point
number
x
= float(3)
print(x)
3.0
format() Formats a specified value
x
= format(0.5, '%')
print(x)
y
= format(255, 'x')
print(y)
50.000000%
Ff
frozenset() Returns a frozenset object
mylist
= ['apple', 'banana', 'cherry']
x
= frozenset(mylist)
print(x)
frozenset({'apple',
'banana', 'cherry'})
getattr() Returns the value of the specified attribute
(property or method)
class
Person:
name = "John"
age = 36
country = "Norway"
x
= getattr(Person, 'age')
print(x)
36
globals() Returns the current global symbol table as a
dictionary
x
= globals()
print(x)
print(x["__file__"])
{'__name__':
'__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external .sourcefileloader="" 0x7ffa31c7f550="" at="" object="">, '__spec__': None, '__annotations__':{}, '__builtins__':
, 'signal': ,
'__file__': 'main.py', '__cached__': None, 'x': {...}}
main.py
hasattr()
Returns True if the specified object has the specified attribute
(property/method)
class
Person:
name = "John"
age = 36
country = "Norway"
x
= hasattr(Person, 'age')
print(x)
True
hex() Converts a number into a hexadecimal value
x
= hex(255)
print(x)
ff
id() Returns the id of an object
x = ('apple', 'banana', 'cherry')
y = id(x)
y = id(x)
print(y)
140027154184808
input() Allowing user input
print('Enter
your name:')
x
= input()
print('Hello,
' + x)
Enter
your name:
89
Hello,
89
int() Returns an integer number
x
= int(3.5)
print(x)
3
isinstance()
Returns True if a specified object is an instance of a specified object
x
= isinstance("Hello", (float, int, str, list, dict, tuple))
print(x)
True
class
myObj:
name = "John"
y
= myObj()
x
= isinstance(y, myObj)
print(x)
True
issubclass() Returns True if a specified class is a
subclass of a specified object
class
myAge:
age = 36
class
myObj(myAge):
name = "John"
age = myAge
x
= issubclass(myObj, myAge)
print(x)
True
iter() Returns an iterator object
x
= iter(["apple", "banana", "cherry"])
print(next(x))
print(next(x))
print(next(x))
apple
banana
cherry
len() Returns the length of an object
mylist
= ["apple", "banana", "cherry"]
x
= len(mylist)
print(x)
3
list() Returns a list
x
= list(('apple', 'banana', 'cherry'))
print(x)
['apple',
'banana', 'cherry']
locals() Returns an updated dictionary of the current
local symbol table
x
= locals()
print(x)
print(x["__file__"])
{'__name__':
'__main__', '__doc__': None, '__package__': None, '__loader__': <_frozen_importlib_external .sourcefileloader="" 0x7f1350c3f550="" at="" object="">, '__spec__': None, '__annotations__':{}, '__builtins__':
, 'signal': ,
'__file__': 'main.py', '__cached__': None, 'x': {...}}
main.py
map() Returns the specified iterator with the
specified function applied to each item
def
myfunc(n):
return len(n)
x
= map(myfunc, ('apple', 'banana', 'cherry'))
for
i in x:
print(i)
5
6
6
def
myfunc(a, b):
return a + b
x
= map(myfunc, ('apple', 'banana', 'cherry'), ('orange', 'lemon',
'pineapple'))
for
i in x:
print(i)
appleorange
bananalemon
cherrypineapple
max() Returns the largest item in an iterable
a
= (1, 5, 3, 9)
x
= max(a)
print(x)
9
x
= max("Mike", "John", "Vicky")
print(x)
Vicky
memoryview()
Returns a memory view object
x
= memoryview(b"Hello")
print(x)
#return
the Unicode of the first character
print(x[0])
#return
the Unicode of the second character
print(x[1])
72
101
min() Returns the smallest item in an iterable
a
= (1, 5, 3, 9)
x
= min(a)
print(x)
1
next() Returns the next item in an iterable
mylist
= iter(["apple", "banana", "cherry"])
x
= next(mylist)
print(x)
x
= next(mylist)
print(x)
x
= next(mylist)
print(x)
[GCC
4.8.2] on linux
apple
banana
cherry
object() Returns a new object
x
= object()
print(x)
x
= object()
print(x)
oct() Converts a number into an octal
x
= oct(12)
print(x)
0o14
open() Opens a file and returns a file object
f
= open("demofile.txt", "r")
print(f.read())
Hello
Jeeva
"r" - Read - Default value.
Opens a file for reading, error if the file does not exist
"a" - Append - Opens a file
for appending, creates the file if it does not exist
"w" - Write - Opens a file for
writing, creates the file if it does not exist
"x" - Create - Creates the
specified file, returns an error if the file exist
In addition you can specify if the file should be
handled as binary or text mode
"t" - Text - Default value.
Text mode
"b" - Binary - Binary mode
(e.g. images)
ord() Convert an integer representing the Unicode
of the specified character
x
= ord("h")
print(x)
x
= ord("h")
print(x)
pow() Returns the value of x to the power of y
x
= pow(4, 3)
print(x)
64
print() Prints to the standard output device
print("Hello",
"how are you?", sep=" ---")
print("Hello",
"how are you?")
x
= ("apple", "banana", "cherry")
print(x)
Hello
---how are you?
Hello
how are you?
('apple',
'banana', 'cherry')
range() Returns a sequence of numbers, starting from
0 and increments by 1 (by default)
x
= range(6)
for
n in x:
print(n)
0
1
2
3
4
5
x
= range(3, 6)
for
n in x:
print(n)
3
4
5
x
= range(3, 20, 2)
for
n in x:
print(n)
3
5
7
9
11
13
15
17
19
reversed() Returns a reversed iterator
alph
= ["a", "b", "c", "d"]
ralph
= reversed(alph)
for
x in ralph:
print(x)
d
c
b
a
round() Rounds a numbers
x
= round(5.76543, 2)
print(x)
x
= round(5.76543)
print(x)
5.77
6
set() Returns a new set object
x
= set(('apple','apple', 'banana', 'cherry'))
print(x)
{'cherry',
'banana', 'apple'}
setattr() Sets an attribute (property/method) of an
object
class
Person:
name = "John"
age = 36
country = "Norway"
setattr(Person,
'age', 40)
slice() Returns a slice object
a
= ("a", "b", "c", "d", "e",
"f", "g", "h")
x
= slice(2)
print(a[x])
a
= ("a", "b", "c", "d", "e",
"f", "g", "h")
x
= slice(3, 5)
print(a[x])
a
= ("a", "b", "c", "d", "e",
"f", "g", "h")
x
= slice(0, 8, 3)
print(a[x])
('a',
'b')
('d',
'e')
('a',
'd', 'g')
sorted() Returns a sorted list
a
= ("b", "g", "a", "d", "f",
"c", "h", "e")
x
= sorted(a)
print(x)
['a',
'b', 'c', 'd', 'e', 'f', 'g', 'h']
a
= ("a", "b", "c", "d", "e",
"f", "g", "h")
x
= sorted(a, reverse=True)
print(x)
['h',
'g', 'f', 'e', 'd', 'c', 'b', 'a']
str() Returns a string object
x
= str(3.5)
print(x)
x
= int("12")
print(x)
3.5
12
sum() Sums the items of an iterator
a
= (1, 2, 3, 4, 5)
x
= sum(a)
print(x)
a
= (1, 2, 3, 4, 5)
x
= sum(a, 7)
print(x)
15
22
tuple() Returns a tuple
x
= tuple(('apple', 'banana', 'cherry'))
print(x)
type() Returns the type of an object
a
= ('apple', 'banana', 'cherry')
b
= "Hello World"
c
= 33
x
= type(a)
y
= type(b)
z
= type(c)
print(x,y,z)
vars()
Returns the __dict__
property of an object
class Person:
...
name = "John"
...
age = 36
...
country = "norway"
...
x
= vars(Person)
print(x)
{'__module__':
'__main__', 'name': 'John', 'age': 36, 'country': 'norway', '__dict__':
, '__weakref__': , '__doc__': None}
zip() Returns an iterator, from two or more
iterators
a
= ("John", "Charles", "Mike")
b
= ("Jenny", "Christy", "Monica")
x
= zip(a, b)
print(x)
for
i in x:
...
print(i)
...
('John',
'Jenny')
('Charles',
'Christy')
('Mike',
'Monica')
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