Python File Operation

In this section, you will learn how to perform operations on files in Python programming.

Using Python you can open a file, read or write something to a file and then close a file. This can be done by using some file manipulating functions. To perform any operation on a file you have to create an object of the file first.

Open a file:

A file can be opened using open() function. A file object is created which is later used to perform operations on the file.

The syntax to open a file is as follows:

obj = open(fileName, mode)

fileName is the name of the file, mode defines the mode in which the file will be opened for example r to open a file in reading mode.

fobj = open("PythonExamplefile.txt", 'r')

The file PythonExamplefile will be opened in read mode.

Modes to open a file:

Modes Meaning
r File is opened in reading mode.
rb File is opened in the reading mode in binary format.
r+ File is opened in both reading and writing modes.
rb+ File is opened in both read and writing mode in binary format.
w File is opened in writing mode. If the file doesn’t exist, a new file will be created. If the file exists, it will be overwritten.
wb File is opened in writing mode in binary format. If the file doesn’t exist, a new file will be created. If the file exists, it will be overwritten.
w+ File is opened in both reading and writing mode. If the file doesn’t exist, a new file will be created for reading and writing. If the file exists, it will be overwritten.
wb+ File is opened in both reading and writing mode in binary format. If the file doesn’t exist, a new file will be created for reading and writing. If the file exists, it will be overwritten.
a File is opened in append mode. The new data will be written at the end of the file. If the file doesn’t exist, a new file will be created for writing.
ab File is opened in append mode in binary format. The new data will be written at the end of the file. If the file doesn’t exist, a new file will be created for reading and writing.
a+ File is opened in both append and reading mode. The new data will be written at the end of the file. If the file doesn’t exist, a new file will be created for reading and writing.
ab+ File is opened in both append and reading mode. The new data will be written at the end of the file. If the file doesn’t exist, a new file will be created for reading and writing.

Close a file:

After performing operations on a file, a file must be closed. The close() method is used to close a file.

fobj.close()
fobj = open("PythonExamplefile.txt", 'r')
#operations on file
fobj.close()

File object:

When a file is opened, a file object is created which can be used to perform operations. For example, you can get information about a file such as its name, the mode in which the file is opened, etc.

fobj = open("PythonExamplefile.txt", 'r')
print("File name", fobj.name)
print("File mode", fobj.mode)
fobj.close()

Result:

File name PythonExamplefile.txt
File mode r

Write a file:

The write() method is used write something on a file. The file must be opened to write on.

The syntax to use write() method is as follows:

fobj.write("string")

Example:

fobj=open("PythonExamplefile.txt", 'w')
fobj.write("Hello Python Programming")
fobj.close()

The following content will be written to the file:

Hello Python Programming

Read a file:

You can read from a file by using the read() method. Reading from a file is getting input from the file.

The following is the syntax to read from a file:

fobj.read(numberofBytes)

Here numberofBytes is the total number of bytes that are read from the file.

fobj=open("PythonExamplefile.txt", 'r')
content = fobj.read(5)
print(content)
fobj.close()
Hello

Rename and remove a file:

Rename a file:

The rename() method is used to rename a file.

The syntax of rename() is as follows:

os.rename(currentName, newName)

Here os is a module which lets you perform functions that are Operating System dependent.

Example:

import os
os.rename("PythonExamplefile.txt", "Python.txt")

The new name of the file is Python.txt now.

Remove a file:

A file is deleted by using remove() method.

The syntax of remove() is as follows:

os.remove(nameofFile)

Example:

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