File Handling in Python

File handling refers to the process of playing with files that involve processes like creating, updating, opening, and deleting files. In this tutorial, we will learn file handling and file manipulation in Python.

Table of Content

• What is File Handling?
• Advantages of File Handling in Python
• Disadvantages of File Handling in Python

What is File Handling?

File handling refers to creating, deleting, updating, reading, and closing the files. In Python, we have some built-in methods for file handling. Files are stored on disk, and Python gives us a way to interact with those files.

Python file-handling operations are also known as Python I/O. It deals with two types of files. They are:

1. Text files
2. Binary files

Let’s learn operations in file handling:

1. Opening a File in Python

To perform any operation on the files in Python, the first step is to open the file. Only then, will we be able to proceed with the next steps. For opening a file in Python, there is a built-in function open(), that takes two arguments: the file name and the mode in which we want to open the file.

Syntax to open a file:

file = open("filename", "mode")

Here, the filename is the name of the file, and mode is the mode of the file in which we want to open the file.

File Modes in Python

Let’s learn the mode of the files in which we can open the file:

2. Writing into a File

If we want to write into a file, we have to use the function file.write(). It will create a new file if it does not exist, and if it does, it will delete all the content and update the new one. We have to use ‘w’mode to write anything in the file.

Example: Using the write() method

Output:

Intellipaat

Explanation:

Here, we have opened the file with the file name(hello.txt) in ‘w’ mode means writing mode, and writing the content, if this file does not exist, it will be created, and the content will be added to that file, and if the file exists, the string ”intellipaat” is overwritten into the file.

Example: using the writelines() method

This method is used to write multiple lines in the file.

Content added

Explanation:

Here we are writing multiple lines into the file, with the help of writelines() function.

Shape Your Career as a Python Developer

Grow with Our Python Training

Explore Program

3. Reading a File

The read() method is used to read data from a file. To read the file we have to open the file in read mode(r). We can read data from a file in Python in three different methods, with these three functions:

• read(): it will read the whole file
• readline(): this function will read one line at a time
• readlines(): this function will read all lines into a list.

Example: Using read() method

Suppose we have a file named hello.txt, and we want to read the data of the file, following code will help us to read the data from the file.

ReactJs, NodeJs, Javascript

Explanation: We have opened the file named hello.txt, read the file with read(), and printed the data.

Example: Using readline() method

This function helps us to read the file line by line.

“Hello”
“Intellipaat”

Explanation: If the file contains two or more lines, then we will use this function to read the file.

Example: Using readlines() method

This function helps us to read all lines and put them into a list. Let’s

Example:

“Hello”
“Intellipaat”

4. Closing a File

To close an opened file in Python, we have to use the close() function. It is necessary to close the file after opening it to release all the resources. It also makes sure the changes made to the files must be saved before closing the file.

Syntax:

file = open('file.txt', 'r')
file.close()    # Close the file

• Using “with” Statement for Automatic File Closing‘with’ statement is used for automatically closing the file. It is the best practice to close the file in Python. It ensures that the file is automatically closed after all the operations completed even after there is an exception occurs. It also reduces the risk of file corruption and resource leakage.

Code:

with open("hello.txt", "r") as file:
   data = file.read()
    print(data)

Explanation: The above code will open the file named hello.txt. Read data from the file, and close the file automatically after printing the data.

• Handling Exceptions When Closing a FileWhen dealing with file operations, it’s important to deal with exceptions while closing the file. This can be done by using a try-finally block that ensures that the file is closed properly.

File Closed

5. Deleting a File in Python

To delete a file in Python, you have to import the module OS, and use the os.remove() function.

Code:

import os
os.remove("hello.txt")

• Checking if the File ExistsBefore deleting the file, we have to check whether the file exists or not to avoid getting an error. Below is the code that helps us check the existence of files.

Other Methods of File Handling in Python

Following are the other common methods of file handling in Python, along with their descriptions: