Find the number of characters in a file using Python

Question

Here is the question:

I have a file with these words:

hey how are you
I am fine and you
Yes I am fine

And it is asked to find the numbe

Answer 1

Sum up the length of all words in a line:

characters += sum(len(word) for word in wordslist)

The whole program:

with open('my_words.txt') as infile:
    lines=0
    words=0
    characters=0
    for line in infile:
        wordslist=line.split()
        lines=lines+1
        words=words+len(wordslist)
        characters += sum(len(word) for word in wordslist)
print(lines)
print(words)
print(characters)

Output:

3
13
35

This:

(len(word) for word in wordslist)

is a generator expression. It is essentially a loop in one line that produces the length of each word. We feed these lengths directly to sum:

sum(len(word) for word in wordslist)

Improved version

This version takes advantage of enumerate, so you save two lines of code, while keeping the readability:

with open('my_words.txt') as infile:
    words = 0
    characters = 0
    for lineno, line in enumerate(infile, 1):
        wordslist = line.split()
        words += len(wordslist)
        characters += sum(len(word) for word in wordslist)

print(lineno)
print(words)
print(characters)

This line:

with open('my_words.txt') as infile:

opens the file with the promise to close it as soon as you leave indentation. It is always good practice to close file after your are done using it.