Check if String Starts with Substring in Python

In this article we are going to check whether the string starts with the substring or not, It is useful for checking whether the string starts with the substring, which is helpful in tasks like filtering data or validating input.

In Python there are various ways to perform this check, such as startswith(), string slicing and regular expression. Let's dive into the article to learn more about them.

Using python startswith() Method

The Python startswith() method is used to check whether the string starts with a given substring or not. This method accepts a prefix string that you want to search for and is invoked on a string object.

This method return true if the string starts with the specified value, or else it returns false.

Syntax

Following is the syntax of python startswith() method ?

str.startswith(value, start, end)

Example 1

Let's look at the following example, where we are going to consider the basic usage of the startswith() method.

str1 = "Welcome to Tutorialspoint"
substr = "Wel"
print(str1.startswith(substr))

Output

Output of the above program is as follows ?

True

Example 2

Consider another scenario, where we are going to use the substring that is not part of the string and observe the output.

str1 = "Ciaz Audi BMW"
substr = "RX100"
print(str1.startswith(substr))

Output

Output of the above program is as follows ?

False

Using python re Module

The python re module supports for the regular expressions, helping in string patterns matching and manipulation. It includes functions like match(), search() to identify, extract or replace patterns in strings.

Example 1

In the following example, we are going to use the re.search() to check whether the string starts with substring or not.

import re
str1 = "Welcome to Tutorialspoint"
substr = "Wel"
print(bool(re.search(substr, str1)))

Output

Following is the output of the above program ?

True

Example 2

Following is the example, where we are going to use the re.match() to check whether the string starts with substring or not.

import re
x = "Welcome Everyone"
y = "Wel"
z = bool(re.match(y, x))
print(z)

Output

Following is the output of the above program ?

True