Python | Split given string into equal halves

We are given a string, we need to split it into two halves. If the string has an odd length, the first half should be longer by one character.

Using String Slicing

String Slicing is the efficient approach which splits the string at the midpoint. If the string length is odd, the first half automatically gets the extra character.

s1 = "GeeksforGeeks"

# Use string slicing to split the string into first and second half
s2, s3 = s1[:len(s1)//2 + len(s1)%2], s1[len(s1)//2 + len(s1)%2:]

print("First half:", s2)
print("Second half:", s3)

First half: Geeksfo
Second half: rGeeks

Explanation:

• s1[:len(s1)//2 + len(s1)%2]: Extracts the first half, adding 1 character if the string has an odd length.
• s1[len(s1)//2 + len(s1)%2:]: Extracts the second half, starting from the midpoint.

Using the divmod() function

divmod() function divides the string length by 2, obtaining the quotient (length of the first part) and remainder. Add the remainder to the quotient if the length is odd. Use slicing to extract the first half as [:q + r] and the second half as [q + r:]

s = "GeeksforGeeks"

# Using divmod to get the quotient (q) and remainder (r) when dividing the string length by 2
q, r = divmod(len(s), 2)

# Slicing the string to get the first half, including the remainder if the length is odd
first, second = s[:q + r], s[q + r:]

print("First half:", first)
print("Second half:", second)

First half: Geeksfo
Second half: rGeeks

Explanation:

• divmod(len(s), 2) divides the length of s by 2, returning the quotient (q) as the midpoint and the remainder (r) to ensure the first half is longer if the length is odd.
• first = s[:q + r] extracts the first half of the string, adding an extra character if the length is odd.
• second = s[q + r:] extracts the second half, starting from the midpoint.

Using islice() from itertools

This method uses islice() to split the string into two halves. It slices the string twice: the first slice from the start to the middle, and the second slice from the middle to the end. The join() function is used to convert the iterator into a string.

from itertools import islice

s1 = "GeeksforGeeks"

# Use islice to get the first half of the string
s2 = ''.join(islice(s, None, len(s)//2 + len(s)%2))

# Use islice to get the second half of the string
s3 = ''.join(islice(s, len(s)//2 + len(s)%2, None))

print("First half:", s2)
print("Second half:", s3)

First half: Geeksfo
Second half: rGeeks

Explanation:

• s2 = ''.join(islice(s, None, len(s)//2 + len(s)%2)) extracts the first half of the string. The slice starts from the beginning (None) to the middle, adding an extra character if the string length is odd (due to len(s)%2).
• s3 = ''.join(islice(s, len(s)//2 + len(s)%2, None)) extracts the second half, starting from the midpoint to the end of the string.