Python count Function

Python count function is useful for counting the number of times a substring is repeated in a given string. This section discusses how to use the Python count function to perform counting with an example.

Python count Syntax

The syntax of the count function in Python Programming Language is

String_Value.count(Sub, Start, End)

Sub: This argument is mandatory. The count Function looks for this substring inside the String_Value, and if the Python count function finds the text, it returns the result.
Start: If you want to count from the middle of a string or at a particular index, specify it here.
End: If you want to find up to the middle of a string or a particular index, specify it here.

This Python count function returns an integer value. For example, If we say, ‘Hell World’.count(‘l’, 0, 7), then it starts looking for l inside the ‘Hello World’ and returns two because the index position of the end value is 7 (i., r)

Python count Function Example

The following set of examples helps to understand the string count Function in this Python Programming Language.

In this Python example, First, we declared two String variables, Str1 and Str2, and assigned corresponding values.

The first statement finds the number of times ‘a’ repeats in the Str1 string and prints the output.

The following Python count statement slices the string Str1 starting at 6 and up to 25. Within the sliced string, it finds the number of times the ‘a’ string will repeat and prints the output.

For Str5, it slices the string Str1 starting at 6 and up to End (To find the end value, we used the len function). Within the sliced string, count the number of times ‘a’ will repeat.

Within the last statement, Str6, we used the function directly on String.

Str1 = 'learn Python at tutorial gateway'
Str2 = 'a'
 
Str3 = Str1.count(Str2)
print("Total Number of a's in String1 = ", Str3)

Str4 = Str1.count(Str2, 6, 25)
print("Total Number of a's in Sliced String1 = ", Str4)

Str5 = Str1.count(Str2, 6, len(Str1))
print("Total Number of a's in Sliced String1 = ", Str5)
 
# Performing directly
Str6 = 'learn Python at tutorial gateway'.count('a', 0, 60)
print("Total Number of a's in String1 = ", Str6)

Python count function Alternative

From the interview perspective, they may ask you to display the letter count without using the built-in method. Here, we use for loop to iterate the characters present in String. The if statement compares characters and increments the counter.

Str1 = 'learn Python at tutorial gateway'
Str2 = 'a'

co = 0

for char in Str1:
           if char == Str2:
                      co = co + 1
print("Total Number of a's in String1 = ", co)

Total Number of a's in String1 = 5

In this program, first, We used For Loop to iterate the characters present in Str1.

Within the for loop, we used the If statement to check whether each string character equals Str2. And if it is True, then the cn value is incremented by 1.

The last print statement prints the Output.

The following example is another alternative method to this Python count function.

from collections import Counter

Str1 = 'learn Python at tutorial gateway'
Str2 = 'a'

cn = Counter(Str1)[Str2]
print("Total Number of a's in String1 = ", cn)

Total Number of a's in String1 = 5