Python: Count Punctuation Marks in a Text File (Solved)

Practice Question 25

In this question, we will learn how to write a function that scans an article and counts the total number of common punctuation marks (., ,, !, ?, :, ;).

The Logic (How it works)

Before writing the code, let us first understand the logic behind the solution.

To count these symbols efficiently, we treat the file as a stream of individual characters:

• Read Character by Character: We use f.read() to get the entire file content.

• Define the Target Set: We create a string variable marks = ".,!?:;" containing all the symbols we want to count.

• The Comparison: For every character in the file, we check if it is “in” our marks string.

• The Counter: If the character exists in our defined set, we increment the count.

Let’s Code as per the above logic :

def countPunctuation():
    f = open("article.txt", "r")
    data = f.read()
    
    # Define the set of punctuation marks we are looking for
    marks = ".,!?:;"
    count = 0
    
    for alpha in data:
        if alpha in marks:
            count += 1
            
    f.close()
    return count

# To call the function and see the result:
print("Total number of punctuation marks:", countPunctuation())

Important Notes for Students

As a teacher, I want you to pay close attention to these points, as they are where most students make mistakes in exams:

• • The Power of in: Using if char in marks is much cleaner than writing if char == '.' or char == ','.... It makes your code faster and easier for the examiner to read.

  • read() for Characters: Since punctuation is a character-level detail, f.read() is the most appropriate method here.

  • Extending the Logic: If you need to count other symbols like @, #, or $, you simply add them to the marks string. No other part of the code needs to change!

Teacher’s Secret Tip for Exams:

Python actually has a built-in collection of all punctuation marks! You can use import string and then check if char in string.punctuation. Using this in a practical exam shows you have advanced knowledge of Python modules!

Want to practice more? If you found this helpful, I have compiled a full list of 30 practice problems just like this one. Each question focuses on a different logic to help you become a pro at File Handling.

Click here to view the full 30-Question Practice Set

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