Python Built-in Functions Reference

This article provides an English reference of Python's built‑in functions, including a brief description and example usage for each function.

Function Name

Description

Usage

abs(x)

Returns the absolute value of a number.

abs(-10)

→

10

all(iterable)

Checks whether all elements in the iterable are true.

all([True, False, 1])

→

False

any(iterable)

Checks whether any element in the iterable is true.

any([False, False, True])

→

True

ascii(object)

Returns an ASCII‑only representation of the object.

ascii('hello')

→

'hello'

bin(x)

Converts an integer to its binary string representation.

bin(10)

→

'0b1010'

bool(x)

Converts the object to a Boolean value.

bool(0)

→

False

chr(i)

Returns the Unicode character corresponding to the integer.

chr(65)

→

'A'

dict(**kwargs / seq)

Creates a dictionary.

dict(one=1, two=2)

or

dict([('one', 1), ('two', 2)])

dir(obj)

Lists all attributes and methods of the object.

dir(str)

divmod(a, b)

Returns a tuple of the quotient and remainder.

divmod(10, 3)

→

(3, 1)

enumerate(iterable, start=0)

Returns an enumerate object yielding pairs of index and value.

list(enumerate(['a', 'b', 'c']))

→

[(0, 'a'), (1, 'b'), (2, 'c')]

eval(expression[, globals[, locals]])

Evaluates the given expression string.

eval("2+2")

→

4

filter(function, iterable)

Filters elements for which the function returns true.

list(filter(lambda x: x % 2 == 0, [1, 2, 3, 4]))

→

[2, 4]

float(x)

Converts a number or string to a floating‑point number.

float("3.14")

→

3.14

format(value[, format_spec])

Formats a value using a format string.

'{} {}'.format('Hello', 'World')

→

'Hello World'

frozenset(iterable)

Creates an immutable set.

frozenset([1, 2, 3])

hash(object)

Returns the hash value of the object.

hash('hello')

hex(x)

Converts an integer to a lowercase hexadecimal string.

hex(255)

→

'0xff'

id(object)

Returns the unique identifier of the object.

id([])

input([prompt])

Reads a line from input, optionally displaying a prompt.

input("Enter your name: ")

int(x[, base])

Converts a number or string to an integer.

int("123", 10)

→

123

len(s)

Returns the length of the object.

len("hello")

→

5

list(iterable)

Converts an iterable to a list.

list(range(5))

→

[0, 1, 2, 3, 4]

map(function, iterable, ...)

Applies a function to each element of the iterable.

list(map(lambda x: x**2, [1, 2, 3]))

→

[1, 4, 9]

max(*args[, key, default])

Returns the largest of the arguments.

max(1, 2, 3)

→

3

min(*args[, key, default])

Returns the smallest of the arguments.

min(1, 2, 3)

→

1

next(iterator[, default])

Returns the next item from the iterator.

next(iter([1, 2, 3]))

→

1

open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

Opens a file and returns a file object.

f = open("file.txt", "w")

pow(base, exp[, mod])

Returns base raised to the power exp (modulo mod if provided).

pow(2, 3)

→

8

print(*objects, sep=' ', end='\n', file=sys.stdout, flush=False)

Prints objects to the console.

print("Hello", "World")

range(stop) / range(start, stop[, step])

Creates an immutable sequence of integers.

for i in range(5): print(i)

Function Name

Description

Usage

reversed(seq)

Returns a reversed iterator.

for i in reversed('abc'): print(i)

round(number[, ndigits])

Rounds a number to a given precision.

round(3.14159, 2)

→

3.14

set(iterable)

Creates an unordered collection of unique elements.

set([1, 2, 2, 3, 4, 4])

→

{1, 2, 3, 4}

slice(start, stop[, step])

Creates a slice object.

range(10)[slice(2, 7, 2)]

sorted(iterable[, key, reverse])

Returns a new sorted list from the iterable.

sorted([3, 1, 4, 1, 5, 9, 2])

→

[1, 1, 2, 3, 4, 5, 9]

str(object='')

Converts an object to its string representation.

str(123)

→

'123'

sum(iterable[, start])

Returns the sum of a sequence of numbers.

sum([1, 2, 3, 4, 5])

→

15

tuple(iterable)

Converts an iterable to a tuple.

tuple('abc')

→

('a', 'b', 'c')

type(object) / type(name, bases, dict)

Returns the type of an object or creates a new type.

type('hello')

/

MyClass = type('MyClass', (object,), {'attr': 'value'})

vars([object])

Returns the __dict__ attribute of an object, or locals if no argument.

class A: pass; a = A(); vars(a)

zip(*iterables)

Aggregates elements from each iterable into tuples.

list(zip('ABCD', 'xy'))

→

[('A', 'x'), ('B', 'y')]

import(name[, globals[, locals[, fromlist[, level]]]])

Dynamically imports a module.

module = __import__('sys')

Function Name

Description

Usage

compile(source, filename, mode[, flags[, dont_inherit]])

Compiles Python source code into a code object.

compile('print("Hello, World!")', '<string>', 'exec')

complex(real[, imag])

Creates a complex number.

complex(1, 2)

→

(1+2j)

delattr(object, name)

Deletes an attribute from an object.

class C: x = 1; c = C(); delattr(c, 'x')

dir([object])

Without arguments, returns names in the current scope; with an object, returns its attributes.

dir()

/

dir(list)

exec(object[, globals[, locals]])

Executes a compiled code object or a string of Python code.

exec('print("Hello, World!")')

globals()

Returns a dictionary representing the current global symbol table.

globals()['__name__']

hasattr(object, name)

Checks whether an object has a given attribute.

hasattr(int, '__add__')

help([object])

Invokes the built‑in help system for the object, or the interactive help if no object is given.

help(print)

hex(x)

Converts an integer to a lowercase hexadecimal string.

hex(255)

→

'0xff'

input([prompt])

Reads a line from input, optionally displaying a prompt.

input('Please enter your name: ')

isinstance(object, classinfo)

Checks if the object is an instance of a class or a tuple of classes.

isinstance('test', str)

issubclass(class, classinfo)

Checks if a class is a subclass of another class or a tuple of classes.

issubclass(int, object)

iter(o[, sentinel])

Returns an iterator for the object; sentinel can be used for special termination.

iter(range(5), 3)

locals()

Returns a dictionary representing the current local symbol table.

Called inside a function:

locals()

Function Name

Description

Usage

oct(x)

Converts an integer to an octal string.

oct(123)

→

'0o173'

ord(c)

Returns the Unicode code point for a single character.

ord('A')

→

65

pow(base, exponent[, modulo])

Computes exponentiation, optionally modulo.

pow(2, 3, 5)

→

3

property(fget=None, fset=None, fdel=None, doc=None)

Creates a property attribute with optional getter, setter, deleter, and docstring.

class C: ...

@property
def value(self): return self._value

repr(object)

Returns a string containing a printable representation of an object.

repr(123)

→

'123'

setattr(object, name, value)

Sets the value of an attribute on an object.

class C: pass; c = C(); setattr(c, 'x', 10)

slice(stop) / slice(start, stop[, step])

Creates a slice object.

s = slice(1, 5); my_list[s]

staticmethod(function)

Converts a function into a static method.

class C: @staticmethod
def method(): pass

super(type[, object-or-type])

Provides a proxy object to delegate method calls to a parent class.

class B(A):
def method(self):
super().method()

zip(*iterables)

Aggregates elements from each iterable into tuples.

list(zip('ABCD', 'xy'))

→

[('A', 'x'), ('B', 'y')]

Function Name

Description

Usage

import(name[, globals[, locals[, fromlist[, level]]]])

Dynamic module import.

math = __import__('math')

callable(object)

Checks if the object appears callable.

callable(abs)

→

True

compile(source, filename, mode[, flags[, dont_inherit]])

Compiles source code into a code object.

code_obj = compile("print('Hello, world!')", "<string>", "exec")

delattr(object, name)

Deletes an attribute from an object.

class C: x = 1; c = C(); delattr(c, 'x')

format(value[, format_spec])

Formats a value using a format specification.

format(3.14159, '.2f')

→

'3.14'

globals()

Returns the dictionary of the current global symbol table.

globals()['__name__']

hasattr(object, name)

Checks if an object has a given attribute.

hasattr(int, '__add__')

help([object])

Shows help information for the object or the interactive help system.

help(print)

intern(string)

Interns a string, improving memory efficiency for many identical strings.

intern('example_string')

memoryview(obj)

Creates a memory‑view object that exposes the buffer interface of the given object.

m = memoryview(b'ABCDEF')

open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

Opens a file and returns a file object.

f = open("file.txt", "w")

property([fget[, fset[, fdel[, doc]]]])

Defines a property with optional getter, setter, deleter, and docstring.

See earlier examples.

vars([object])

Returns the __dict__ of an object, or locals if no argument is given.

class C: x = 1; c = C(); vars(c)