Python Built-in Functions Tutorial

Python provides a rich set of built-in functions that you can use to perform common tasks. In this tutorial, we will explore some of the most commonly used built-in functions, along with examples and explanations.

1. len()

The len() function returns the length (the number of items) of an object. The object can be a sequence (such as a string, list, or tuple) or a collection (such as a dictionary).

example_list = [1, 2, 3, 4, 5]
print(len(example_list))  # Output: 5

example_string = "Hello, World!"
print(len(example_string))  # Output: 13

2. type()

The type() function returns the type of an object.

example_int = 10
print(type(example_int))  # Output: 

example_list = [1, 2, 3]
print(type(example_list))  # Output: 

3. max() and min()

The max() function returns the largest item in an iterable or the largest of two or more arguments. The min() function returns the smallest item in an iterable or the smallest of two or more arguments.

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

print(max(10, 20, 30))  # Output: 30
print(min(10, 20, 30))  # Output: 10

4. sum()

The sum() function returns the sum of all items in an iterable.

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

numbers_with_start = [1, 2, 3]
print(sum(numbers_with_start, 10))  # Output: 16 (10 + 1 + 2 + 3)

5. sorted()

The sorted() function returns a new sorted list from the elements of any iterable.

unsorted_list = [3, 1, 4, 1, 5, 9]
print(sorted(unsorted_list))  # Output: [1, 1, 3, 4, 5, 9]

unsorted_string = "python"
print(sorted(unsorted_string))  # Output: ['h', 'n', 'o', 'p', 't', 'y']

6. abs()

The abs() function returns the absolute value of a number.

negative_number = -10
print(abs(negative_number))  # Output: 10

negative_float = -7.5
print(abs(negative_float))  # Output: 7.5

7. round()

The round() function rounds a floating-point number to the nearest integer. You can also specify the number of decimal places to round to.

floating_number = 3.14159
print(round(floating_number))  # Output: 3

print(round(floating_number, 2))  # Output: 3.14

8. pow()

The pow() function returns the value of x to the power of y (x^y). It can also take a third argument, the modulo z, which will return (x^y) % z.

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

print(pow(base, exponent, 5))  # Output: 3 (2^3 % 5)

9. all() and any()

The all() function returns True if all elements of the iterable are true (or if the iterable is empty). The any() function returns True if any element of the iterable is true. If the iterable is empty, any() returns False.

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

10. enumerate()

The enumerate() function adds a counter to an iterable and returns it as an enumerate object.

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

Conclusion

Python's built-in functions provide a powerful and easy way to perform common tasks. Understanding how to use these functions will help you write more efficient and readable code.