When working with text in Python, it is often necessary to search for specific patterns or words within a given string. One common task is to perform a boolean text search, where we want to determine whether a certain word or phrase exists in the text or not.

Option 1: Using the ‘in’ operator

One simple way to perform a boolean text search in Python is by using the ‘in’ operator. This operator allows us to check if a substring exists within a larger string. Here’s an example:

text = "This is a sample text"
search_word = "sample"

if search_word in text:
    print("The word is present in the text")
else:
    print("The word is not present in the text")

In this example, we define a variable ‘text’ that contains the sample text. We also define a variable ‘search_word’ that contains the word we want to search for. We then use the ‘in’ operator to check if the ‘search_word’ exists in the ‘text’ string. If it does, we print a message indicating that the word is present. Otherwise, we print a message indicating that the word is not present.

Option 2: Using regular expressions

If we need more advanced pattern matching capabilities, we can use regular expressions in Python. Regular expressions allow us to define complex patterns and search for them within a string. Here’s an example:

import re

text = "This is a sample text"
search_pattern = r"bsampleb"

if re.search(search_pattern, text):
    print("The word is present in the text")
else:
    print("The word is not present in the text")

In this example, we import the ‘re’ module, which provides functions for working with regular expressions. We define a variable ‘search_pattern’ that contains the regular expression pattern we want to search for. The pattern ‘bsampleb’ matches the word ‘sample’ as a whole word. We then use the ‘re.search()’ function to search for the pattern within the ‘text’ string. If a match is found, we print a message indicating that the word is present. Otherwise, we print a message indicating that the word is not present.

Option 3: Using the ‘find()’ method

Another way to perform a boolean text search in Python is by using the ‘find()’ method. This method returns the index of the first occurrence of a substring within a string, or -1 if the substring is not found. Here’s an example:

text = "This is a sample text"
search_word = "sample"

if text.find(search_word) != -1:
    print("The word is present in the text")
else:
    print("The word is not present in the text")

In this example, we use the ‘find()’ method to search for the ‘search_word’ within the ‘text’ string. If the method returns a value other than -1, it means that the word is present in the text. We print a message accordingly. Otherwise, we print a message indicating that the word is not present.

After considering these three options, the best approach depends on the specific requirements of your task. If you only need to check for the existence of a simple word or phrase, using the ‘in’ operator is the simplest and most straightforward option. However, if you need more advanced pattern matching capabilities, such as searching for whole words or using complex patterns, using regular expressions or the ‘find()’ method may be more suitable.