Python Built-in Functions

Python is packed with a wide range of built-in functions that simplify coding tasks, enhance productivity, and minimize the need for external libraries. At The Coding College, we’re committed to helping you harness the power of these functions to build efficient and effective code.

This guide explores Python’s built-in functions, their applications, and practical examples to accelerate your learning journey.

What are Built-in Functions in Python?

Built-in functions in Python are pre-defined functions that are always available for use. They are part of the Python Standard Library, which means you don’t need to import any module to use them. These functions save time and effort by performing common tasks such as:

  • Data type conversions.
  • Mathematical operations.
  • String manipulations.
  • Input/output handling.

List of Python Built-in Functions

Here’s a categorized list of commonly used built-in functions:

1. Input/Output Functions

  • print(): Displays output to the screen. 
print("Welcome to Python!")
  • input(): Accepts user input. 
name = input("Enter your name: ")
print(f"Hello, {name}")

2. Type Conversion Functions

Convert data types using these functions:

  • int(): Converts to an integer. 
num = int("10")  # Output: 10
  • float(): Converts to a floating-point number. 
num = float("10.5")  # Output: 10.5
  • str(): Converts to a string. 
text = str(100)  # Output: "100"
  • bool(): Converts to a boolean value. 
is_true = bool(1)  # Output: True

3. Mathematical Functions

Perform mathematical operations effortlessly:

  • abs(): Returns the absolute value. 
print(abs(-5))  # Output: 5
  • round(): Rounds a number to the nearest integer. 
print(round(3.7))  # Output: 4
  • pow(): Raises a number to a power. 
print(pow(2, 3))  # Output: 8

4. String Functions

Manipulate strings easily:

  • len(): Returns the length of a string. 
print(len("Python"))  # Output: 6
  • ord(): Converts a character to its Unicode code. 
print(ord("A"))  # Output: 65
  • chr(): Converts a Unicode code to a character. 
print(chr(65))  # Output: "A"

5. Data Structure Functions

Work with lists, dictionaries, and more:

  • min(): Returns the smallest value. 
numbers = [1, 2, 3]
print(min(numbers))  # Output: 1
  • max(): Returns the largest value. 
print(max(numbers))  # Output: 3
  • sum(): Returns the sum of elements in an iterable. 
print(sum(numbers))  # Output: 6
  • sorted(): Returns a sorted version of a list. 
print(sorted(numbers))  # Output: [1, 2, 3]

6. Utility Functions

Helpful tools for everyday coding tasks:

  • id(): Returns the unique ID of an object. 
x = 5
print(id(x))
  • type(): Returns the data type of an object. 
print(type(x))  # Output: <class 'int'>
  • help(): Displays the documentation of a function or object. 
help(len)

Advanced Built-in Functions

Working with Iterables

  • map(): Applies a function to each item in an iterable. 
numbers = [1, 2, 3]
squared = map(lambda x: x ** 2, numbers)
print(list(squared))  # Output: [1, 4, 9]
  • filter(): Filters items in an iterable based on a condition. 
even_numbers = filter(lambda x: x % 2 == 0, numbers)
print(list(even_numbers))  # Output: [2]
  • zip(): Combines two or more iterables into tuples. 
names = ["Alice", "Bob"]
scores = [85, 90]
print(list(zip(names, scores)))  # Output: [('Alice', 85), ('Bob', 90)]

Working with Files

  • open(): Opens a file for reading or writing. 
with open("file.txt", "r") as file:
    print(file.read())

Benefits of Using Built-in Functions

  1. Ease of Use: Simplifies common coding tasks.
  2. Performance: Optimized for efficiency.
  3. Versatility: Covers a wide range of programming needs.
  4. Reliability: Thoroughly tested and maintained as part of Python.

Conclusion

Built-in functions are a cornerstone of Python programming, allowing you to write cleaner, faster, and more efficient code. By mastering these functions, you’ll significantly enhance your productivity and problem-solving skills.

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