Python File isatty() Method

The terminal device that performs input and output operations one character at a time is called a “tty”, which stands for teletypewriter. In Python, the inbuilt method “file.isatty()” of the IOBase class is used to check if a file stream is interactive. This means that this method can read and write characters one by one.

This guide will talk about:


What is the “file.isatty()” Method in Python?

In Python, the “file.isatty()” method is utilized to compute whether the file stream is interactive, or it is connected/linked to a terminal device.





No parameters

Return Value

The “file.isatty()” method retrieves “True” if the file stream is interactive and “False” otherwise.

Example: Checking if the File is Connected/Linked to a Terminal Device

In the below code, we opened the file named “new.txt” in read mode and then called the “file.isatty()” method on the file object. If the file is connected to a terminal device, the method will return True, and if it is not, the method will return False:

file = open("new.txt", "r")


The above code executed the below output:

Here, the file is opened in “w” mode and checks the interactive file stream using the “file.isatty()” method:

file = open("new.txt", "w")


After executing the above code, the following output will be displayed:

Advantages and Disadvantages of “file.isatty()” Method

The “file.isatty()” method in Python checks if a program runs in a terminal. This helps the interactive program handle user input or output better. For example, a program can use “isatty()” to avoid reading input from a file or skip terminal formatting.

However, the “isatty()” method only works for terminal devices, not other files. It may also behave differently on different systems or be tricked by terminal simulators.


The “file.isatty()” approach in Python is utilized to determine whether the specified file stream is interactive or attached to a terminal device. We opened the file in various modes, such as read, write, or append, and checked whether the file connected to the terminal. This guide presented a detailed guide on Python’s “file.isatty()” method utilizing several examples.

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Haroon Javed

Hi, I'm Haroon. I am an electronics engineer and a technical content writer. I am a tech geek who loves to help people to the best of my knowledge.