Python – Get number of characters, words, spaces and lines in a file

Last Updated : 28 Aug, 2023

Given a text file fname, the task is to count the total number of characters, words, spaces, and lines in the file.

Python – Get number of characters, words, spaces and lines in a file

As we know, Python provides multiple in-built features and modules for handling files. Let’s discuss different ways to calculate the total number of characters, words, spaces, and lines in a file using Python.

Get the number of characters, words, spaces, and lines in a file

Below are the methods that we will cover in this article:

The naive approach of getting the number of characters, words, spaces, and lines in a file.
Using some built-in functions and OS module functions

Count the Number of Lines, Words, and Characters using the Native Method

In this approach, the idea is to solve the task by developing our own logic. Without using any built-in function of Python, the total number of characters, words, spaces and lines of the file will be calculated. Below is the implementation of the above approach.

Python3

# Function to count number of characters, words, spaces and lines in a file
def counter(fname):
 
    # variable to store total word count
    num_words = 0
     
    # variable to store total line count
    num_lines = 0
     
    # variable to store total character count
    num_charc = 0
     
    # variable to store total space count
    num_spaces = 0
     
    # opening file using with() method
    # so that file gets closed
    # after completion of work
    with open(fname, 'r') as f:
         
        # loop to iterate file
        # line by line
        for line in f:
             
            # incrementing value of num_lines with each
            # iteration of loop to store total line count
            num_lines += 1
             
            # declaring a variable word and assigning its value as Y
            # because every file is supposed to start with a word or a character
            word = 'Y'
             
            # loop to iterate every
            # line letter by letter
            for letter in line:
                 
                # condition to check that the encountered character
                # is not white space and a word
                if (letter != ' ' and word == 'Y'):
                     
                    # incrementing the word
                    # count by 1
                    num_words += 1
                     
                    # assigning value N to variable word because until
                    # space will not encounter a word can not be completed
                    word = 'N'
                     
                # condition to check that the encountered character is a white space
                elif (letter == ' '):
                     
                    # incrementing the space
                    # count by 1
                    num_spaces += 1
                     
                    # assigning value Y to variable word because after
                    # white space a word is supposed to occur
                    word = 'Y'
                     
                # loop to iterate every character
                for i in letter:
                     
                    # condition to check white space
                    if(i !=" " and i !="\n"):
                         
                        # incrementing character
                        # count by 1
                        num_charc += 1
                         
    # printing total word count
    print("Number of words in text file: ",
          num_words)
     
    # printing total line count
    print("Number of lines in text file: ",
          num_lines)
     
    # printing total character count
    print('Number of characters in text file: ',
          num_charc)
     
    # printing total space count
    print('Number of spaces in text file: ',
          num_spaces)
     
# Driver Code:
if __name__ == '__main__':
    fname = 'File1.txt'
    try:
        counter(fname)
    except:
        print('File not found')

Output:

Number of words in text file:  25
Number of lines in text file:  4
Number of characters in text file:  91
Number of spaces in text file:  21

Time complexity: O(n) where n is the number of characters in the file.
Space complexity: O(1) as only a few variables are used to store the count and no additional data structures are used.

Find the number of characters in a file using Python

In this approach, the idea is to use the os.linesep() method of OS module to separate the lines on the current platform. When the interpreter’s scanner encounter os.linesep it replaces it with \n character. After that strip() and split() functions will be used to carry out the task. Get more ideas about strip() and split() functions. Below is the implementation of the above approach.

Python3

import os
 
# Function to count number
# of characters, words, spaces
# and lines in a file
def counter(fname):
     
    # variable to store total word count
    num_words = 0
     
    # variable to store total line count
    num_lines = 0
     
    # variable to store total character count
    num_charc = 0
     
    # variable to store total space count
    num_spaces = 0
     
    # opening file using with() method
    # so that file gets closed
    # after completion of work
    with open(fname, 'r') as f:
         
        # loop to iterate file
        # line by line
        for line in f:
             
            # separating a line from \n character
            # and storing again in line
            line = line.strip(os.linesep)
             
            # splitting the line
            wordslist = line.split()
             
            # incrementing value of num_lines
            num_lines = num_lines + 1
             
            # incrementing value of num_word
            num_words = num_words + len(wordslist)
             
            # incrementing value of num_char
            num_charc = num_charc + sum(1 for c in line
                        if c not in (os.linesep, ' '))
             
            # incrementing value of num_space
            num_spaces = num_spaces + sum(1 for s in line
                                if s in (os.linesep, ' '))
     
    # printing total word count
    print("Number of words in text file: ",
          num_words)
     
    # printing total line count
    print("Number of lines in text file: ",
          num_lines)
     
    # printing total character count
    print("Number of characters in text file: ",
          num_charc)
     
    # printing total space count
    print("Number of spaces in text file: ",
          num_spaces)
 
# Driver Code:
if __name__ == '__main__':
    fname = 'File1.txt'
    try:
        counter(fname)
    except:
        print('File not found')

Output:

Number of words in text file:  25
Number of lines in text file:  4
Number of characters in text file:  91
Number of spaces in text file:  21

Time complexity: O(n), where n is the number of characters in the file. The code reads the file line by line and performs operations on each line, so the time complexity grows linearly with the size of the file.
Space complexity: O(1), as the code only uses a constant amount of memory to store the count variables, regardless of the size of the file.