Python | Get duplicate tuples from list

• Last Updated : 21 Nov, 2019

Sometimes, while working with records, we can have a problem of extracting those records which occur more than once. This kind of application can occur in web development domain. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using list comprehension + `set() + count()`
Initial approach that can be applied is that we can iterate on each tuple and check it’s count in list using `count()`, if greater than one, we can add to list. To remove multiple additions, we can convert the result to set using `set()`.

 `# Python3 code to demonstrate working of``# Get duplicate tuples from list``# Using list comprehension + set() + count()`` ` `# initialize list``test_list ``=` `[(``3``, ``4``), (``4``, ``5``), (``3``, ``4``), ``             ``(``3``, ``4``), (``4``, ``5``), (``6``, ``7``)]`` ` `# printing original list ``print``(``"The original list : "` `+` `str``(test_list))`` ` `# Get duplicate tuples from list``# Using list comprehension + set() + count()``res ``=` `list``(``set``([ele ``for` `ele ``in` `test_list``            ``if` `test_list.count(ele) > ``1``]))`` ` `# printing result``print``(``"All the duplicates from list are : "` `+` `str``(res))`

Output :

```The original list : [(3, 4), (4, 5), (3, 4), (3, 4), (4, 5), (6, 7)]
All the duplicates from list are : [(4, 5), (3, 4)]
```

Method #2 : Using `Counter() + items()` + list comprehension
The combination of above functions can also be used to perform this particular task. In this, we just get the count of each occurrence of element using `Counter()` as dictionary and then extract all those whose value is above 1.

 `# Python3 code to demonstrate working of``# Get duplicate tuples from list``# Using list comprehension + Counter() + items()``from` `collections ``import` `Counter`` ` `# initialize list``test_list ``=` `[(``3``, ``4``), (``4``, ``5``), (``3``, ``4``), ``             ``(``3``, ``4``), (``4``, ``5``), (``6``, ``7``)]`` ` `# printing original list ``print``(``"The original list : "` `+` `str``(test_list))`` ` `# Get duplicate tuples from list``# Using list comprehension + Counter() + items()``res ``=` `[ele ``for` `ele, count ``in` `Counter(test_list).items()``                                          ``if` `count > ``1``]`` ` `# printing result``print``(``"All the duplicates from list are : "` `+` `str``(res))`

Output :

```The original list : [(3, 4), (4, 5), (3, 4), (3, 4), (4, 5), (6, 7)]
All the duplicates from list are : [(4, 5), (3, 4)]
```

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