Python Built In Functions

by

Python Built In Functions

Introduction

Python is a powerful and versatile programming language that comes with a rich set of built-in functions. These functions are pre-defined and readily available, making it easier for developers to accomplish various tasks without having to write the code from scratch. In this tutorial, we will explore what built-in functions are in Python, provide examples of some commonly used built-in functions, and explain the difference between built-in functions and user-defined functions.

What are Built-in Functions in Python?

Built-in functions are functions that are built into the Python programming language. They are always available and do not require any additional installations or imports. These functions are designed to perform common tasks and operations on different types of data. Python provides a wide range of built-in functions, which can be broadly categorized into the following types:

  1. Mathematical Functions: These functions perform various mathematical operations such as calculating absolute values, rounding numbers, finding maximum and minimum values, and more.
  2. String Functions: String functions handle operations on strings, such as concatenation, case conversions, finding substrings, and more.
  3. List Functions: List functions deal with operations on lists, including sorting, adding elements, removing elements, and more.
  4. Dictionary Functions: These functions work with dictionaries, enabling operations like accessing keys, values, merging dictionaries, etc.
  5. File Input/Output Functions: File-related functions help in reading from and writing to files.
  6. Type Conversion Functions: Type conversion functions allow you to convert data from one type to another, such as converting integers to strings or vice versa.
  7. Other Utility Functions: Python also provides several other utility functions for tasks like input/output, formatting, etc.

Now, let’s explore some examples of commonly used built-in functions in Python.

Examples of Python Built-in Functions:

  1. Mathematical Functions:
  1. String Functions:
  1. List Functions:
  1. Dictionary Functions:
  1. File Input/Output Functions:

Difference Between Built-in Functions and User-defined Functions:

The primary difference between built-in functions and user-defined functions lies in their origin and availability. Built-in functions are provided by the Python language itself and are readily available for use without any additional code. On the other hand, user-defined functions are created by the developers themselves to perform specific tasks and are not available in the language by default. Here’s an example to illustrate the difference:

User-defined Function:

Built-in Function:

In the user-defined function example, we define a function called “square” that takes a parameter “x” and returns its square. In the built-in function example, we use the “sum” function, which is already provided by Python, to calculate the sum of the elements in the list.

Difference between Built-in functions and anonymous functions (also known as lambda functions)

In Python, the main difference between built-in functions and anonymous functions (also known as lambda functions) lies in their structure, creation, and usage.

Built-in Functions:

Built-in functions in Python are pre-defined functions that are provided by the Python language itself. They are readily available for use without any additional coding or import statements. These functions cover a wide range of tasks and operations, such as mathematical calculations, string manipulations, list operations, file I/O, etc. They are named and can be used repeatedly throughout the code. Here’s an example of using a built-in function to find the length of a list:

In this example, the len() function is a built-in function that returns the number of elements in the list numbers.

Anonymous Functions (Lambda Functions):

Lambda functions are a special type of function in Python that allows you to create small, one-line functions without explicitly defining them using the def keyword. Lambda functions are typically used for simple, one-time tasks and are often used in conjunction with higher-order functions like map(), filter(), and reduce(). Lambda functions have the following structure: lambda arguments: expression

The lambda function takes a set of arguments, performs the specified expression on those arguments, and returns the result of the expression. Here’s an example of a lambda function that calculates the square of a number:

In this example, we create a lambda function that takes an argument x, calculates the square using the expression x**2, and then we call the lambda function with square(5) to calculate the square of 5.

Key Differences:

  1. Structure and Definition: Built-in functions are predefined and come with Python, whereas lambda functions are created on-the-fly and are not explicitly defined using the def keyword.
  2. Usage and Complexity: Built-in functions are used for a wide range of tasks and can be complex with multiple parameters, whereas lambda functions are typically used for simple operations with one or few parameters.
  3. Naming: Built-in functions have names, and you can call them using their names whenever needed. Lambda functions, on the other hand, do not have names and are often used as temporary, inline functions.
  4. Return Statement: Built-in functions return their results as any other function, using the return statement. Lambda functions automatically return the value of the expression without using the return statement.
  5. Use Cases: Built-in functions are ideal for general-purpose and reusable tasks, while lambda functions are more suited for immediate, short-term, and one-time uses.

Leave a Comment