Online Ethical Hacking Course

Apply Now

Examples

Program to Remove Punctuations From String in Python

In text processing and data manipulation, the presence of punctuation marks can sometimes hinder the accurate analysis of textual data. Punctuation marks are symbols used in writing to help in understanding and interpreting sentences. 

However, when performing certain tasks such as text mining, natural language processing, or sentiment analysis, it is often beneficial to remove these punctuation marks from the text.

In this tutorial, we will explore a Python program to remove punctuations from a string. We will provide a step-by-step guide, complete with code examples and explanations, to help you understand the concept and implement it in your Python programs effectively.

Understanding how to remove punctuation from a string in Python is a fundamental skill in text processing and analysis. Punctuations can include characters such as periods, commas, exclamation marks, question marks, and more. Removing punctuations enables us to perform tasks such as tokenization, counting word frequencies, or extracting meaningful information from the text.

The importance of removing punctuations extends beyond text processing. In many cases, textual data collected from various sources, such as social media or online forums, may contain noisy or irrelevant punctuation marks. By mastering the art of removing a punctuation from a string in Python, you can enhance the accuracy of your text analysis and gain valuable insights from the textual data. You can use the online Python Compiler to practice the given Python Programs.

How to Remove Punctuation from String Using Python NLTK

To remove punctuation from a string in Python using the Natural Language Toolkit (NLTK) library, you can use the nltk.tokenize module. 

Code

import nltk
import string

def remove_punctuations(text):
    # Tokenize the text into individual words
    words = nltk.word_tokenize(text)

    # Remove punctuations from each word
    words_without_punctuations = [word for word in words if word not in string.punctuation]

    # Join the words back into a string
    text_without_punctuations = " ".join(words_without_punctuations)


    return text_without_punctuations

# Test the function
input_text = input("Enter a string: ")
text_without_punctuations = remove_punctuations(input_text)
print("String without punctuations:", text_without_punctuations)

Output

Enter a string: Let's learn @Python - by Tutorials Freak.
String without punctuations: Lets learn Python  by Tutorials Freak

Explanation

  • In this program, we import the nltk library and the string module.

  • The remove_punctuations function takes a text argument, which is the input string from which we want to remove punctuations. It tokenizes the text into individual words using the nltk.word_tokenize function.

  • Next, it filters out the words that are not present in the string.punctuation constant, effectively removing the punctuations from the words.

  • Finally, it joins the filtered words back into a string using the join function with a space as the separator. The resulting string without punctuations is stored in the text_without_punctuations variable and returned.

To use the program, the user is prompted to enter a string. The remove_punctuations function is called with the input text as the argument. The resulting string without punctuations is then displayed.

Make sure to install the NLTK library and download the required resources by running nltk.download('punkt') before using the program.

Python Course

How to Remove Punctuation from String in Python Using Regex?

To remove punctuation from a string in Python using regular expressions (regex), you can use the re module.

Code

import re

def remove_punctuations(text):
    # Define the pattern to match punctuation characters
    pattern = r"[^\w\s]"

    # Remove punctuations using regex substitution
    text_without_punctuations = re.sub(pattern, "", text)

    return text_without_punctuations

# Test the function
input_text = input("Enter a string: ")
text_without_punctuations = remove_punctuations(input_text)
print("String without punctuations:", text_without_punctuations)

Output

Enter a string: I love @Tutorials Freak!
String without punctuations: I love Tutorials Freak

Explanation

  • In this program, we import the re module to work with regular expressions.

  • The remove_punctuations function takes a text argument, which is the input string from which we want to remove punctuations. It defines a regex pattern r"[^\w\s]" that matches any character that is not a word character (alphanumeric or underscore) or whitespace.

  • The re.sub function is then used to substitute all occurrences of the pattern with an empty string, effectively removing the punctuation characters from the text. The resulting string without punctuations is stored in the text_without_punctuations variable and returned.

Python Program to Remove Punctuations From String: Video