Python Built-in Functions

Python Built-in Functions and Methods Guide

Numeric Functions

abs

• Returns the absolute value of a number.
• Syntax: abs(number)

num = -10
abs_num = abs(num)
print(abs_num)  # Output: 10

divmod

• Returns the quotient and remainder of division.
• Syntax: divmod(x, y)

quotient, remainder = divmod(10, 3)
print(quotient, remainder)  # Output: 3 1

max

• Returns the largest item in an iterable or among arguments.
• Syntax: max(iterable, *args, key=None)

numbers = [1, 5, 2, 8, 3]
max_num = max(numbers)
print(max_num)  # Output: 8

min

• Returns the smallest item in an iterable or among arguments.
• Syntax: min(iterable, *args, key=None)

numbers = [1, 5, 2, 8, 3]
min_num = min(numbers)
print(min_num)  # Output: 1

pow

• Returns x to the power of y.
• Syntax: pow(base, exp, mod=None)

result = pow(2, 3)
print(result)  # Output: 8

round

• Rounds a number to a specified precision in decimal digits.
• Syntax: round(number[, ndigits])

num = 3.14159
rounded_num = round(num, 2)
print(rounded_num)  # Output: 3.14

sum

• Returns the sum of elements in an iterable.
• Syntax: sum(iterable, start=0)

numbers = [1, 2, 3, 4, 5]
total = sum(numbers)
print(total)  # Output: 15

String Methods

chr

• Returns the string representing a character whose Unicode code point is the integer.
• Syntax: chr(i)

char = chr(65)
print(char)  # Output: 'A'

format

• Formats a specified value into a specified format.
• Syntax: format(value, format_spec)

formatted = format(123.456, ".2f")
print(formatted)  # Output: '123.46'

ord

• Returns the Unicode code point for a given character.
• Syntax: ord(c)

unicode_value = ord('A')
print(unicode_value)  # Output: 65

str

• Returns a string version of an object.
• Syntax: str(object='')

num_str = str(123)
print(num_str)  # Output: '123'

Container Methods

dict

• Creates a new dictionary.
• Syntax: dict(**kwargs) or dict(iterable, **kwargs)

my_dict = dict(name='John', age=30)
print(my_dict)  # Output: {'name': 'John', 'age': 30}

frozenset

• Returns an immutable frozenset object.
• Syntax: frozenset([iterable])

my_frozenset = frozenset({1, 2, 3})
print(my_frozenset)  # Output: frozenset({1, 2, 3})

list

• Returns a list object.
• Syntax: list(iterable=())

my_list = list(range(5))
print(my_list)  # Output: [0, 1, 2, 3, 4]

set

• Returns a new set object.
• Syntax: set([iterable])

my_set = set([1, 2, 3])
print(my_set)  # Output: {1, 2, 3}

tuple

• Returns a tuple object.
• Syntax: tuple([iterable])

my_tuple = tuple([1, 2, 3])
print(my_tuple)  # Output: (1, 2, 3)

Type Conversion Functions

bool

• Returns the boolean value of an object.
• Syntax: bool([value])

bool_value = bool(0)
print(bool_value)  # Output: False

float

• Returns a floating-point number from a number or string.
• Syntax: float([x])

float_num = float("3.14")
print(float_num)  # Output: 3.14

hex

• Converts an integer to a lowercase hexadecimal string prefixed with '0x'.
• Syntax: hex(x)

hex_value = hex(255)
print(hex_value)  # Output: '0xff'

int

• Returns an integer object from a number or string.
• Syntax: int([x])

int_num = int("123")
print(int_num)  # Output: 123

oct

• Converts an integer to an octal string prefixed with '0o'.
• Syntax: oct(x)

oct_value = oct(8)
print(oct_value)  # Output: '0o10'

Other Functions

all

• Returns True if all elements of an iterable are true.
• Syntax: all(iterable)

items = [True, True, False]
print(all(items))  # Output: False

any

• Returns True if any element of an iterable is true.
• Syntax: any(iterable)

items = [False, False, True]
print(any(items))  # Output: True

bin

• Converts an integer to a binary string prefixed with '0b'.
• Syntax: bin(x)

bin_value = bin(5)
print(bin_value)  # Output: '0b101'

enumerate

• Returns an enumerate object that yields tuples of index and value.
• Syntax: enumerate(iterable, start=0)

letters = ['a', 'b', 'c']
for index, value in enumerate(letters):
    print(index, value)
# Output:
# 0 a
# 1 b
# 2 c

filter

• Constructs an iterator from elements of an iterable for which a function returns true.
• Syntax: filter(function, iterable)

def is_even(num):
    return num % 2 == 0

numbers = [1, 2, 3, 4, 5]
even_numbers = list(filter(is_even, numbers))
print(even_numbers)  # Output: [2, 4]

map

• Applies a function to all items in an input iterable.
• Syntax: map(function, iterable, ...)

def square(x):
    return x ** 2

numbers = [1, 2, 3, 4, 5]
squared_numbers = list(map(square, numbers))
print(squared_numbers)  # Output: [1, 4, 9, 16, 25]

sorted

• Returns a new sorted list from the elements of any iterable.
• Syntax: sorted(iterable, *, key=None, reverse=False)

numbers = [5, 2, 3, 1, 4]
sorted_numbers = sorted(numbers)
print(sorted_numbers)  # Output: [1, 2, 3, 4, 5]

super

• Returns a proxy object that delegates method calls to a parent or sibling class.
• Syntax: super([type[, object-or-type]])

class Parent:
    def __init__(self, name):
        self.name = name

class Child(Parent):
    def __init__(self, name, age):
        super().__init__(name)
        self.age = age

child = Child("John", 10)
print(child.name, child.age)  # Output: John 10

Input and Output Functions

input

• Reads a line from input, converts it to a string (stripping a trailing newline), and returns it.
• Syntax: input(prompt)

name = input("Enter your name: ")
print("Hello, " + name + "!")

print

• Prints objects to the text stream file, separated by sep and followed by end.
• Syntax: print(*objects, sep=' ', end='\n', file=sys.stdout, flush=False)

print("Hello", "World", sep=", ", end="!\n")
# Output: Hello, World!