Count number of sentences in a string in Python

Hello friends, sometimes you may have a long text to read and count the number of sentences in that text. Instead of counting the full stops all by yourself, you can write a simple piece of code in Python. In this tutorial, I will tell you how you can count the number of sentences in a string.

Count the number of sentences in a string

I have used two methods to perform this task.

• without predefined function
• with predefined function

Without predefined function

I have taken a multiline string, for example, stored in a temporary variable, string. I have then initialized two empty lists as string_list and l respectively. Now to iterate every character of the string I have run a for loop with 0 as its starting value and the length of the string as its end value.

Code :

string = '''This is CodeSpeedy Technologies Pvt Ltd. We are software development & app development company. We can turn your idea into digital reality. We provide digital and tech solutions for businesses. Our team is always committed to fulfill your requirements.'''

string_list = []
l = []
for i in range(0, len(string)):
    if string[i] != ".":
        string_list.append(string[i])  
     elif string[i] == "." and string[i+1].isspace(): 
        l.append(string_list)
        string_list = []
    
print(len(l))

Check if the string character at the ith position is not a full stop. If yes, append the iterated character of the string to string_list. Else, append the string_list to the list, l. After the for loop ends, I have printed the length of the list, l using the len() function.

Output :

5

With predefined function

You can count the number of sentences in a string, by using two functions split() and len(). I have used the split() function by passing a full stop as an argument, this acts as a separator between two sentences. split() function returns a list of all the sentences separated by a full stop. However, it also considers a whitespace beyond the last full top. This is why while printing the length of the list, string_list using the len() function I have subtracted 1 from it.

Code :

string_list = string.split(".")
print(len(string_list)-1)

However, the split() function will consider any other full stop between the sentences, for example, ‘Mr.’ .

Output :

5

Now you can count the number of sentences present in the string using Python.