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Python | Swap tuple elements in list of tuples
• Last Updated : 27 Aug, 2019

While doing competitive programming, one can come across a question in which one requires to work with 2D plane and work with coordinates. One such subproblem can be swapping x, y coordinate elements. Let’s discuss certain ways in which this problem can be solved using tuple element swapping.

Method #1 : Using list comprehension
This is just a brute method to perform the longer method of loop for swapping the elements. In this a new list of tuple is created rather than an inplace swap.

 `# Python3 code to demonstrate working of``# Swap tuple elements in list of tuples``# Using list comprehension`` ` `# initializing list``test_list ``=` `[(``3``, ``4``), (``6``, ``5``), (``7``, ``8``)]`` ` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))`` ` `# Swap tuple elements in list of tuples``# Using list comprehension``res ``=` `[(sub[``1``], sub[``0``]) ``for` `sub ``in` `test_list]``         ` `# printing result``print``(``"The swapped tuple list is : "` `+` `str``(res))`
Output :
```The original list is : [(3, 4), (6, 5), (7, 8)]
The swapped tuple list is : [(4, 3), (5, 6), (8, 7)]
```

Method #2 : Using `map()` + lambda
Yet another way to perform this task is using `map` and lambda. This is a bit slower in execution but a more compact way to perform this task.

 `# Python3 code to demonstrate working of``# Swap tuple elements in list of tuples``# Using map() + lambda`` ` `# initializing list``test_list ``=` `[(``3``, ``4``), (``6``, ``5``), (``7``, ``8``)]`` ` `# printing original list``print``(``"The original list is : "` `+` `str``(test_list))`` ` `# Swap tuple elements in list of tuples``# Using map() + lambda``res ``=` `list``(``map``(``lambda` `sub: (sub[``1``], sub[``0``]), test_list))``         ` `# printing result``print``(``"The swapped tuple list is : "` `+` `str``(res))`
Output :
```The original list is : [(3, 4), (6, 5), (7, 8)]
The swapped tuple list is : [(4, 3), (5, 6), (8, 7)]
```

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