How to check whether a string starts with XYZ in Python?

A string is a collection of characters stored as a single value. Unlike other technologies, there is no need to explicitly declare strings in Python ? you just need to assign strings to a variable, making Python strings easy to use.

Python provides several methods to check if a string starts with a specific substring. The most common approaches are using the built-in startswith() method and regular expressions.

Using startswith() Method

The startswith() method is the simplest and most efficient way to check if a string begins with a specific substring. It returns True if the string starts with the given prefix, otherwise False.

Syntax

string.startswith(prefix, start, end)

Parameters:

• prefix ? The substring to check for
• start (optional) ? Starting position
• end (optional) ? Ending position

Example 1

Here's how to check if a string starts with "Wel" ?

text = "Welcome to Tutorialspoint"
prefix = "Wel"

print("The given string is:", text)
print("The given substring is:", prefix)
print("Starts with 'Wel':", text.startswith(prefix))

The given string is: Welcome to Tutorialspoint
The given substring is: Wel
Starts with 'Wel': True

Example 2

Checking if the same string starts with "XYZ" ?

text = "Welcome to Tutorialspoint"
prefix = "XYZ"

print("The given string is:", text)
print("The given substring is:", prefix)
print("Starts with 'XYZ':", text.startswith(prefix))

The given string is: Welcome to Tutorialspoint
The given substring is: XYZ
Starts with 'XYZ': False

Using Regular Expressions

Regular expressions provide another way to check string patterns. The ^ symbol matches the beginning of a string, making it useful for checking prefixes.

Example 1

Using re.search() with the ^ anchor ?

import re

text = "Welcome to Tutorialspoint"
prefix = "Wel"

print("The given string is:", text)
print("The given substring is:", prefix)
print("Starts with 'Wel':", bool(re.search("^Wel", text)))

The given string is: Welcome to Tutorialspoint
The given substring is: Wel
Starts with 'Wel': True

Example 2

Testing with "XYZ" prefix ?

import re

text = "Welcome to Tutorialspoint"
prefix = "XYZ"

print("The given string is:", text)
print("The given substring is:", prefix)
print("Starts with 'XYZ':", bool(re.search("^XYZ", text)))

The given string is: Welcome to Tutorialspoint
The given substring is: XYZ
Starts with 'XYZ': False

Comparison

Conclusion

The startswith() method is the preferred way to check if a string begins with a specific substring due to its simplicity and performance. Use regular expressions only when you need complex pattern matching capabilities.