# Python | Count vowels in a string

Here, we are going to learn how to count vowels in a string in Python? Here, we have a string with vowels and consonants, we have to count the vowels. By IncludeHelp Last updated : February 12, 2024

## Problem statement

Given a string, and we have to count the total number of vowels in the string using python program.

### Example

The following is the sample input and output:

```Input:
Str = "Hello world"

Output:
Total vowels are: 3
```

## Python - Counting vowels in a string

To count the total number of vowels in a string, use for ... in loop to extract characters from the string, check whether the character is a vowel or not, and if the character is a vowel, then increase the counter.

Note

To check vowel alphabets, check the characters with uppercase and lowercase vowels.

## Python program to count vowels in a string

The below example counts the total number of vowels in the given string.

```# count vowels in a string

# declare, assign string
str = "Hello world"

# declare count
count = 0

# iterate and check each character
for i in str:
# check the conditions for vowels
if (
i == "A"
or i == "a"
or i == "E"
or i == "e"
or i == "I"
or i == "i"
or i == "O"
or i == "o"
or i == "U"
or i == "u"
):
count += 1

# print count
print("Total vowels are: ", count)
```

### Output

The output of the above program is:

```Total vowels are:  3
```

## Implement the program by creating functions to check vowel and to count vowels

Here, we are creating two functions:

### 1) isVowel()

This function will take character as an argument, and returns True, if character is vowel.

### 2) countVowels()

This function will take string as an argument, and return total number of vowels of the string.

## Python program to count the number of vowels in a string

The below example counts the total number of vowels in the given string using the user-defined functions:

```# count vowels in a string

# function to check character
# is vowel or not
def isVowel(ch):
# check the conditions for vowels
if (
ch == "A"
or ch == "a"
or ch == "E"
or ch == "e"
or ch == "I"
or ch == "i"
or ch == "O"
or ch == "o"
or ch == "U"
or ch == "u"
):
return True
else:
return False

def countVowel(s):
# declare count
count = 0
# iterate and check characters
for i in str:
if isVowel(i) == True:
count += 1
return count

# Main code
# declare, assign string
str = "Hello world"

# print count
print("Total vowels are: ", countVowel(str))
```

### Output

The output of the above program is:

```Total vowels are:  3
```

To understand the above examples, you should have the basic knowledge of the following Python topics: