How to Alternate vowels and consonants in Python Strings?

Alternating vowels and consonants in a string means rearranging characters so that consonants and vowels appear in alternating positions. Python provides several approaches using built-in functions like zip(), lambda functions, and zip_longest().

Using join() and zip() Methods

This approach separates vowels and consonants into different lists, then combines them alternately using zip() ?

Algorithm

• Step 1 ? Initialize two empty lists for vowels and consonants

• Step 2 ? Iterate through the string to separate vowels and consonants

• Step 3 ? Use zip() to pair consonants with vowels

• Step 4 ? Use join() to create the alternating string

Example

# Empty lists to hold vowels and consonants
vow_str = []
con_str = []

# Input string
str_1 = "Welcome to Paris"

# Iterate through the string
for char in str_1:
    # Check if character is alphabetic
    if char.isalpha():
        if char.lower() in 'aeiou':
            # Add vowels to vowel list
            vow_str.append(char)
        else:
            # Add consonants to consonant list
            con_str.append(char)

# Alternate consonants and vowels using zip()
output_str = ''.join([a + b for a, b in zip(con_str, vow_str)])
print("Original string:", str_1)
print("Alternating result:", output_str)

Original string: Welcome to Paris
Alternating result: WelocemotaPi

Using Lambda Functions

Lambda functions provide a concise way to filter vowels and consonants from the string ?

Example

# Input string
str_1 = "Welcome Home"

# Define vowels
vowels = 'aeiou'

# Lambda functions to filter vowels and consonants
vowel_filter = lambda char: char.lower() in vowels and char.isalpha()
consonant_filter = lambda char: char.lower() not in vowels and char.isalpha()

# Filter vowels and consonants
vow_str = list(filter(vowel_filter, str_1))
con_str = list(filter(consonant_filter, str_1))

# Create alternating string
output_str = ''.join([a + b for a, b in zip(con_str, vow_str)])

print("Original string:", str_1)
print("Vowels found:", vow_str)
print("Consonants found:", con_str)
print("Alternating result:", output_str)

Original string: Welcome Home
Vowels found: ['e', 'o', 'e', 'o', 'e']
Consonants found: ['W', 'l', 'c', 'm', 'H', 'm']
Alternating result: WelocemoHme

Using zip_longest() Function

The zip_longest() function handles cases where vowels and consonants have different counts by filling missing values ?

Example

from itertools import zip_longest

# Input string
str_1 = "Welcome home"

# Define vowels
vowels = 'aeiou'

# Separate vowels and consonants using list comprehension
vow_str = [char for char in str_1 if char.lower() in vowels]
con_str = [char for char in str_1 if char.isalpha() and char.lower() not in vowels]

# Use zip_longest to handle unequal lengths
output_str = ''.join([a + b for a, b in zip_longest(con_str, vow_str, fillvalue='')])

print("Original string:", str_1)
print("Vowels:", vow_str)
print("Consonants:", con_str)
print("Alternating result:", output_str)

Original string: Welcome home
Vowels: ['e', 'o', 'e', 'o', 'e']
Consonants: ['W', 'l', 'c', 'm', 'h', 'm']
Alternating result: WelocemohmE

Comparison

Conclusion

Use zip_longest() when vowels and consonants have different counts. For equal counts, zip() is simpler. Lambda functions provide a functional approach to filtering characters.