Python open() Method

What is the python open() method?

The open() is an I/O function of python that helps to open text files and returns the respected file object.

The syntax of open() is:

open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

open() Parameters

The open() takes multiple parameters as argument:

• file - Path to the file with the file name.
• mode - mode represents the attributes of a file while opening it. More details of mode parameters are explained in the table below.
• buffering (Optional) - used to set up the buffering policy. Defaults id -1.
• encoding (Optional) - The encoding format to encode or decode the file.
• errors (Optional) - The string specifying how to handle encoding and decoding errors.
• newline (Optional) - how newlines mode works (available values: None, ‘ ‘, ‘\n’, ‘r’, and ‘\r\n’.
• closefd (Optional) - If a filename is given, it must be True. If False, the file descriptor will be kept open when the file is closed.
• opener (Optional) - A custom file opener that will return an open file descriptor.

More about the mode parameter is listed below.

Mode	Description
‘r’	Read - Opening a file for reading. It will be the Default mode.
‘w’	Write - Open a file to write, or it will create the new files if it does not exist.
‘x’	Create - Creating a new file, if file exists, it will return an error
‘a’	Append - Opening a file to append the new content into it. If files do not exist, they will create new ones.
‘t’	Text - Open file in text mode. Default.
‘b’	Binary - Open file in binary mode.
‘+’	Open file for updating (reading and writing)

Let’s check some examples of the open() function in python.

Example 1: How to open a file in python?

# opens test.text file of the current directory
f = open("test.txt")

# specifying the full path
f = open("C:/TEXTFILE.txt")

In the ablow example, we are opening a file, and we are not taking any mode as by default; it will take Read as the default mode.

Example 2: How to use different modes in python open()?

# opens the file in reading mode
f = open("path_to_file", mode='r')

# opens the file in writing mode 
f = open("path_to_file", mode = 'w')

# opens for writing to the end 
f = open("path_to_file", mode = 'a')

Rules of open()

• The open() function will be read as the default mode and the text file as the default file type.
• If the file is not found, it raises the FileNotFoundError exception.

We recommended reading Python File Input/Output for better understanding.