Isascii method in String Python

In this Python tutorial, we will see what is the Isascii method in String Python, its syntax, Parameter, return values, and some illustration examples. And we will also see when we should use Isascii() string method.

In Python, string methods are a set of built-in functions that allow us to manipulate and analyze textual data. Among these methods, the isascii() stands out for its ability to quickly identify if all characters in a string belong to the ASCII character set.

ASCII, or American Standard Code for Information Interchange, is a character encoding standard that represents text in computers. It initially consisted of 128 characters, including alphabets (both lowercase and uppercase), digits, punctuation marks, and control characters. ASCII values range from 0 to 127, each mapping to a specific character. For instance, the ASCII value for ‘A’ is 65, and for ‘a’ is 97.

What is the isascii method in string Python?

Python’s string isascii() method checks if all characters in a given Python string are ASCII characters. If they are, it returns True; otherwise, it returns False.


The syntax of the isascii() method in string Python:


The str is the Python string on which the operation is going to be held.


The Python string isascii method doesn’t accept any parameters.

Return value:

The Python isascii method in string returns: Boolean value

  • True– If all characters in the Python string are ASCII characters.
  • False– If the Python string contains at least one character that is not an ASCII character.

The Isascii() function in string Python example

The isascii() method is an efficient way to quickly check if a given string adheres to the ASCII standard, which can be particularly useful in various data validation scenarios:

When to use isascii() in Python string

  • Data Validation: Before processing strings, especially if the source can contain non-ASCII characters.
  • Interoperability: When working with systems or applications that only accept ASCII characters.
  • Storage Constraints: When saving data in formats or databases that have limitations on character encoding.

Example-1: The basic string isascii() method in Python

The Python isascii method will return True if all the characters are in the given Python string, otherwise False.

For instance, If we have a list of U.S. landmarks, and we want to ensure they’re in ASCII:

landmark = "Grand Canyon"

The output will be: Here, there are non-ASCII characters in the Python string so,

Isascii method in string python with True return value

However, let’s consider a scenario where the landmark name has a special character and see what the isascii() method return in Python.

landmark = "Statue of Liberty🗽"

The output is: Because of the emoji present in the Python string, which is outside the ASCII range

string isascii method in Python with False return value.

This way, we can use the isacii() method in Python string to find whether the string contains any ASCII characters or not.

Example-2: To filter the data stored within a list of Python strings using the isascii() method

If we’re building a system that only accepts addresses with ASCII characters, we can use Python string isascii() to filter out addresses with non-ASCII characters within the list comprehension method in Python.

addresses = ["123 Main St.", "456 Elm St.", "789 Pine St🌲"]
ascii_addresses = [addr for addr in addresses if addr.isascii()]


The output is:

['123 Main St.', '456 Elm St.']
Python isascii method in sting with list comprehension.

This way we can use to filter data stored in a list using the isascii() method in Python string.

Read: Isidentifier method in String Python


In the process of understanding what the isascii() method in string Python is? The syntax, Parameter, and return value, of the isascii method in String Python, can be immensely beneficial, especially when dealing with data consistency and validation in Python. These examples provided above not only give context but also highlight the Python isascii method’s practical applicability in real-world scenarios.

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