# Python – Remove Kth Index Duplicates in Tuple

• Last Updated : 03 Jul, 2020

Sometimes, while working with Python records, we can have a problem in which we need to remove all the tuples, which have similar Kth index elements in list of records. This kind of problem is common in day-day and web development domain. Let’s discuss certain ways in which this task can be performed.

Input : test_list = [(4, 5, 6), (2, 3, 4), (1, 3, 4), (7, 6, 4), (1, 2, 6)], K = 1
Output : [(4, 5, 6), (2, 3, 4), (7, 6, 4), (1, 2, 6)]

Input : test_list = [(4, 5, 6), (2, 3, 4), (1, 3, 4), (7, 6, 4), (1, 2, 6)], K = 0
Output : [(4, 5, 6), (2, 3, 4), (1, 3, 4), (7, 6, 4)]

Method #1 : Using loop
This is one of the ways in which this task can be performed. In this, we perform the task of memoizing already occurred Kth index element in set, and check each time with new value.

 `# Python3 code to demonstrate working of ``# Remove Kth Index Duplicates in Tuple``# Using loop`` ` `# initializing lists``test_list ``=` `[(``4``, ``5``, ``6``), (``2``, ``3``, ``4``), (``1``, ``3``, ``4``), (``7``, ``6``, ``4``), (``1``, ``2``, ``6``)]`` ` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))`` ` `# initializing K``K ``=` `2`` ` `# Remove Kth Index Duplicates in Tuple``# Using loop``keep ``=` `set``()      ``res ``=` `[]``for` `sub ``in` `test_list:``    ``if` `sub[K] ``not` `in` `keep:``        ``res.append(sub)``        ``keep.add(sub[K])``         ` `# printing result ``print``(``"Filtered Tuples : "` `+` `str``(res)) `
Output :
```The original list is : [(4, 5, 6), (2, 3, 4), (1, 3, 4), (7, 6, 4), (1, 2, 6)]
Filtered Tuples : [(4, 5, 6), (2, 3, 4)]
```

Method #2 : Using `groupby() + itemgetter()` + list comprehension
The combination of above functions can be used to solve this problem. In this, we perform the task of checking for Kth element using itemgetter() and groupby() is used to form groups, out of which we extract 1st element by accessing 0th index.

 `# Python3 code to demonstrate working of ``# Remove Kth Index Duplicates in Tuple``# Using groupby() + itemgetter() + list comprehension``from` `itertools ``import` `groupby``from` `operator ``import` `itemgetter`` ` `# initializing lists``test_list ``=` `[(``4``, ``5``, ``6``), (``2``, ``3``, ``4``), (``1``, ``3``, ``4``), (``7``, ``6``, ``4``), (``1``, ``2``, ``6``)]`` ` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))`` ` `# initializing K``K ``=` `2`` ` `# Remove Kth Index Duplicates in Tuple``# Using groupby() + itemgetter() + list comprehension``res ``=` `res ``=` `[``list``(val)[``0``] ``for` `key, val ``in` `groupby(``sorted``(test_list, ``                        ``key ``=` `itemgetter(K)), key ``=` `itemgetter(K))]``         ` `# printing result ``print``(``"Filtered Tuples : "` `+` `str``(res)) `
Output :
```The original list is : [(4, 5, 6), (2, 3, 4), (1, 3, 4), (7, 6, 4), (1, 2, 6)]
Filtered Tuples : [(4, 5, 6), (2, 3, 4)]
```

My Personal Notes arrow_drop_up