Print the even and odd index characters of a string in python

In this post, we will learn how to print the characters at even and odd index of a string in Python. With this program, you will learn how to check if a value is even or odd, how to iterate through a string in python and how to read characters of a string in python.

This program will take one string as input from the user and it will print all the characters at even and odd positions in two different strings.

What are even and odd values:

A number is called even if it is perfectly divisible by 2. That means, if we are dividing that number by 2, the remainder will be 0. For example, 4 is an even number.

We can use modulo, % operator to check if a number is even or odd in python. If n is the number, n%2 will be always 0 if n is even.

Similarly, a number is called odd if it is not perfectly divisible by 2. If we divide the number by 2, the remainder will be 1 always. For example, 11 is odd.

Algorithm:

To solve this problem, we can use the below algorithm:

  • Create two empty arrays to hold the even and odd index characters.
  • Take the string as input from the user.
  • Iterate through the characters of the string one by one.
  • For each character, check the index is even or odd. Insert that character to even or odd index array.

Python program:

Below is the complete python program:

given_string = input('Enter a string: ')

even_chars = []
odd_chars = []

for i in range(len(given_string)):
    if i % 2 == 0:
        even_chars.append(given_string[i])
    else:
        odd_chars.append(given_string[i])

print('Odd characters: {}'.format(odd_chars))
print('Even characters: {}'.format(even_chars))

Here,

  • given_string is the user input string. We are taking this string as input from the user and storing it in given_string.
  • even_chars and odd_chars are arrays to hold the even and odd index characters. We are initialize them as empty arrays.
  • The for loop is iterating through the characters of the string one by one. It checks the current index value and appends the character to even_chars or odd_chars based on the current index.
  • The last two lines are printing the content of odd_chars and even_chars, i.e. all odd and even characters.

Sample Output:

If you run this program, it will print output as like below:

Enter a string: hello
Odd characters: ['e', 'l']
Even characters: ['h', 'l', 'o']

Enter a string: lazyfox
Odd characters: ['a', 'y', 'o']
Even characters: ['l', 'z', 'f', 'x']

You can also add the characters to an empty string instead of using arrays.

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