Creating a Custom Vowel Iterator in Python

Here’s a Python function that iterates a string to find vowels comparing vowels list. It results in a vowel list in the output. It is a helpful example for data analysts.

Table of contents

1. Iterating a string: An Example Code
2. Step-by-step explanation

Iterating a string: An Example Code

Precisely, use init, iter, and next methods in a Class. Here is an explanation.

class VowelIterator:
  def __init__(self, string):
      self.string = string
      self.index = 0
  def __iter__(self):
      return self
  def __next__(self):
      vowels = ['a', 'e', 'i', 'o', 'u']
      while self.index < len(self.string):
          char = self.string[self.index]
          self.index += 1
          if char.lower() in vowels:
              return char
      raise StopIteration


my_string = "Srini Blog"
vowels = VowelIterator(my_string)
for vowel in vowels:
  print(vowel, end=" ")

Output

i i o

Step-by-step explanation

class VowelIterator:
    def __init__(self, string):
        self.string = string
        self.index = 0

    def __iter__(self):
        return self

    def __next__(self):
        vowels = ['a', 'e', 'i', 'o', 'u']

        while self.index < len(self.string):
            char = self.string[self.index]
            self.index += 1

            if char.lower() in vowels:
                return char

        raise StopIteration

Initializes the string in the __init__() method. The __iter__() method initiates iteration. Here, the index variable keeps track of the current position in the string.  

The process in the __next__() method is to iterate each string character. It then compares each character to the vowel list. If a vowel is found, it returns the vowel. And the loop continues. In the end, it raises StopIteration to break the loop.