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)
ordict(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!