How to Find Word in String Python

There are three main methods to find a word in a string in Python:

• The in keyword
• The str.find() method
• Regular expression

1. The "in" keyword method

In Python, the in keyword is used as a membership operator. We can use this operator to find the word in a string.

Here is an example:

text = "This is a sample sentence."
word_to_find = "sample"

if word_to_find in text:
    print("Word found!")
else:
    print("Word not found.")

Output:

Word found!

As you can see, we've found the word "sample" in the text.

the str.find() method

The str.find() method returns the index of the substring if it exists or -1 if it does not exist. To find a word in a string using the str.find() method, you can use the following example:

text = "This is a sample sentence."
word_to_find = "sample"

index = text.find(word_to_find)

if index != -1:
    print(f"Word found at index {index}.")
else:
    print("Word not found.")

Regular expressions method

Another method to find a word in a string is using regular expressions. To find a word in a string using regular expressions, use the following example:

import re

text = "This is a sample sentence."
word_to_find = "sample"

if re.search(r'\b' + re.escape(word_to_find) + r'\b', text):
    print("Word found!")
else:
    print("Word not found.")

However, in the above example, we've used the re.search() function to search for the pattern in the string. 

The re.search() function returns a match object if the pattern is found in the string and None if the pattern is not found.