Mostly used Built-in Functions in Python

Mostly used functions in Python…

print(): Prints the specified value or values. Example: print("Hello, World!") Output: Hello, World!
input(): Reads a line from the console and returns it as a string. Example: name = input("What is your name? ") Output: What is your name? John
len(): Returns the length of an object (string, list, tuple, etc.). Example: my_list = [1, 2, 3, 4, 5] and print(len(my_list)) Output: 5
max(): Returns the largest item in an iterable or the largest of two or more arguments. Example: numbers = [10, 20, 30, 40, 50] and print(max(numbers)) Output: 50
min(): Returns the smallest item in an iterable or the smallest of two or more arguments. Example: numbers = [10, 20, 30, 40, 50] and print(min(numbers)) Output: 10
abs(): Returns the absolute value of a number. Example: x = -10 and print(abs(x)) Output: 10
round(): Returns a floating-point number rounded to a specified number of decimal places. Example: x = 3.14159 and print(round(x, 2)) Output: 3.14
int(): Converts a number or string to an integer. Example: x = "42" and print(int(x)) Output: 42
float(): Converts a number or string to a floating-point number. Example: x = "3.14" and print(float(x)) Output: 3.14
str(): Converts an object to a string. Example: x = 42 and print(str(x)) Output: "42"
bool(): Converts a value to a boolean (True or False). Example: x = 0 and print(bool(x)) Output: False
ord(): Returns an integer representing the Unicode character. Example: print(ord('A')) Output: 65
chr(): Returns a string representing a Unicode character. Example: print(chr(65)) Output: 'A'
range(): Returns a sequence of numbers starting from a specified beginning and ending at a specified end. Example: for i in range(5): and print(i) Output: 0 1 2 3 4
sorted(): Returns a new sorted list from the elements of its argument. Example: numbers = [3, 1, 4, 1, 5, 9] and print(sorted(numbers)) Output: [1, 1, 3, 4, 5, 9]
reversed(): Returns a reverse iterator over the elements of an iterable. Example: my_list = [1, 2, 3, 4, 5] and print(list(reversed(my_list))) Output: [5, 4, 3, 2, 1]
zip(): Returns an iterator of tuples, where the i-th tuple contains the i-th element from each of the argument sequences or iterables. Example: names = ['Alice', 'Bob', 'Charlie'] and ages = [25, 30, 35] and print(list(zip(names, ages))) Output: [('Alice', 25), ('Bob', 30), ('Charlie', 35)]
map(): Returns an iterator that applies a function to each item of an iterable. Example: numbers = [1, 2, 3, 4, 5] and print(list(map(lambda x: x**2, numbers))) Output: [1, 4, 9, 16, 25]
filter(): Returns an iterator that filters elements from an iterable based on a condition. Example: numbers = [1, 2, 3, 4, 5] and print(list(filter(lambda x: x % 2 == 0, numbers))) Output: [2, 4]
reduce(): Applies a rolling function to the elements of an iterable. Example: from functools import reduce and numbers = [1, 2, 3, 4, 5] and print(reduce(lambda x, y: x + y, numbers)) Output: 15
all(): Returns True if all elements of an iterable are true. Example: my_list = [True, True, True] and print(all(my_list)) Output: True
any(): Returns True if at least one element of an iterable is true. Example: my_list = [False, True, False] and print(any(my_list)) Output: True
enumerate(): Returns an iterator that produces tuples containing the index and value for each item in an iterable. Example: my_list = ['apple', 'banana', 'cherry'] and print(list(enumerate(my_list))) Output: [(0, 'apple'), (1, 'banana'), (2, 'cherry')]
zip_longest(): Returns an iterator that aggregates elements from each of the iterables. Example: names = ['Alice', 'Bob', 'Charlie'] and ages = [25, 30] and print(list(zip_longest(names, ages, fillvalue=0))) Output: [('Alice', 25), ('Bob', 30), ('Charlie', 0)]
itertools.count(): Returns a count object that produces a sequence of numbers starting from a specified number. Example: import itertools and counter = itertools.count(start=10, step=2) and print(list(itertools.islice(counter, 5))) Output: [10, 12, 14, 16, 18]
itertools.cycle(): Returns an iterator that produces elements from an iterable in a cycle. Example: import itertools and colors = ['red', 'green', 'blue'] and for color in itertools.cycle(colors): and print(color) Output: red green blue red green blue ... (continues indefinitely)
itertools.repeat(): Returns an iterator that produces a specified value repeatedly. Example: import itertools and print(list(itertools.repeat(42, 3))) Output: [42, 42, 42]
itertools.chain(): Returns an iterator that produces elements from each of the iterables. Example: import itertools and numbers = [1, 2, 3] and letters = ['a', 'b', 'c'] and print(list(itertools.chain(numbers, letters))) Output: [1, 2, 3, 'a', 'b', 'c']
itertools.compress(): Returns an iterator that filters elements from an iterable based on a condition. Example: import itertools and data = [1, 2, 3, 4, 5] and selectors = [True, False, True, False, True] and print(list(itertools.compress(data, selectors))) Output: [1, 3, 5]
itertools.dropwhile(): Returns an iterator that drops elements from the start of an iterable until a condition is met. Example: import itertools and numbers = [2, 4, 6, 8, 10, 1, 3, 5] and print(list(itertools.dropwhile(lambda x: x % 2 == 0, numbers))) Output: [1, 3, 5]

These built-in functions cover a wide range of functionality, from basic data manipulation to advanced itertools operations. Mastering these functions can significantly improve your Python programming efficiency and productivity.

Citations:

[1] https://blog.hubspot.com/website/python-built-in-functions
[2] https://www.shiksha.com/online-courses/articles/different-types-of-python-built-in-functions/
[3] https://sunscrapers.com/blog/30-built-in-python-modules-you-should-be-using-now/
[4] https://realpython.com/python-built-in-functions/
[5] https://www.simplilearn.com/tutorials/python-tutorial/python-functions
[6] https://www.linkedin.com/pulse/introduction-python-data-types-built-in-functions-suraj-kumar-soni
[7] https://www.geeksforgeeks.org/python-functions/
[8] https://www.digitalocean.com/community/tutorials/built-in-python-3-functions-for-working-with-numbers