# Python | Find mismatch item on same index in two list

• Last Updated : 26 Jul, 2021

Given two list of integers, the task is to find the index at which the element of two list doesn’t match.

```Input:
Input1 = [1, 2, 3, 4]
Input2 = [1, 5, 3, 6]

Output: [1, 3]
Explanation:
At index=1 we have 2 and 5 and at index=3
we have 4 and 6 which mismatches.```

Below are some ways to achieve this task.
Method #1: Using Iteration

## Python3

 `# Python code to find the index at which the``# element of two list doesn't match.` `# List initialisation``Input1 ``=` `[``1``, ``2``, ``3``, ``4``]``Input2 ``=` `[``1``, ``5``, ``3``, ``6``]` `# Index initialisation``y ``=` `0` `# Output list initialisation``Output ``=` `[]` `# Using iteration to find``for` `x ``in` `Input1:``    ``if` `x !``=` `Input2[y]:``        ``Output.append(y)``    ``y ``=` `y ``+` `1` `# Printing output``print``(Output)`

Output:

`[1, 3]`

Method #2: Using list Comprehension and zip

## Python3

 `# Python code to find the index at which the``# element of two list doesn't match.` `# List initialisation``Input1 ``=` `[``1``, ``2``, ``3``, ``4``]``Input2 ``=` `[``1``, ``5``, ``3``, ``6``]` `# Using list comprehension and zip``Output ``=` `[Input2.index(y) ``for` `x, y ``in``       ``zip``(Input1, Input2) ``if` `y !``=` `x]` `# Printing output``print``(Output)`

Output:

`[1, 3]`

Method #3: Using Enumerate

## Python3

 `# Python code to find the index at which the``# element of two list doesn't match.` `# List initialisation``Input1 ``=` `[``1``, ``2``, ``3``, ``4``]``Input2 ``=` `[``1``, ``5``, ``3``, ``6``]` `# Using list comprehension and enumerate``Output ``=` `[index ``for` `index, elem ``in` `enumerate``(Input2)``                           ``if` `elem !``=` `Input1[index]]` `# Printing output``print``(Output)`

Output:

`[1, 3]`

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