Python – Remove similar index elements in Strings

Given two strings, removed all elements from both, which are same at similar index.

Input : test_str1 = ‘geels’, test_str2 = ‘beaks’
Output : gel, bak
Explanation : e and s are removed as occur in same indices.

Input : test_str1 = ‘geeks’, test_str2 = ‘geeks’
Output : ”, ”
Explanation : Same strings, all same index, hence removed.

Method #1 : Using loop + zip() + join()

In this, we pair elements with its index using join(), and check for inequality to filter only dissimilar elements in both strings, join() is used to convert result in strings.

Python3

# Python3 code to demonstrate working of
# Remove similar index elements in Strings
# Using join() + zip() + loop

# initializing strings
test_str1 = 'geeks'
test_str2 = 'beaks'

# printing original strings
print("The original string 1 is : " + str(test_str1))
print("The original string 2 is : " + str(test_str2))

# conversion to list for zipping
list1 = list(test_str1)
list2 = list(test_str2)
res1 = []
res2 = []
for ch1, ch2 in zip(list1, list2):

    # check inequalities
    if ch1 != ch2:
        res1.append(ch1)
        res2.append(ch2)

# conversion to string
res1 = "".join(res1)
res2 = "".join(res2)

# printing result
print("Modified String 1 : " + str(res1))
print("Modified String 2 : " + str(res2))

Output

The original string 1 is : geeks
The original string 2 is : beaks
Modified String 1 : ge
Modified String 2 : ba

Method #2 : Using list comprehension

Performs task using similar method as above, just one-liner to perform task in compact form.

Python3

# Python3 code to demonstrate working of
# Remove similar index elements in Strings
# Using list comprehension

# initializing strings
test_str1 = 'geeks'
test_str2 = 'beaks'

# printing original strings
print("The original string 1 is : " + str(test_str1))
print("The original string 2 is : " + str(test_str2))

# one-liner to solve problem
res = ["".join(mastr) for mastr
      in zip(*[(a, b) for a, b in zip(test_str1, test_str2) if a != b])]

# printing result
print("Modified String 1 : " + str(res[0]))
print("Modified String 2 : " + str(res[1]))

Output

The original string 1 is : geeks
The original string 2 is : beaks
Modified String 1 : ge
Modified String 2 : ba