# Python – Remove the row if all elements equal to N

• Last Updated : 29 Dec, 2019

Sometimes, while handling data, especially in Machine Learning domain, we need to go through a lot of similar of N equal data. We sometimes need to eliminate the rows which are all equal to N. Let’s discuss certain ways to remove the rows that have all N values as list columns.

Method #1 : Using list comprehension +` count() + len()`
We can perform this particular task using the list comprehension recipe, partnered with the combination of len and count function to check for similarity element counter equating to the length of list.

 `# Python3 code to demonstrate``# N row deletion in Matrix``# using list comprehension + count() + len()`` ` `# initializing matrix``test_list ``=` `[[``1``, ``4``, ``2``], [``False``, ``9``, ``3``],``            ``[``6``, ``6``, ``6``], [``1``, ``0``, ``1``]]`` ` `# printing original list``print``(``"The original list : "` `+` `str``(test_list))`` ` `# initializing N ``N ``=` `6`` ` `# using list comprehension + count() + len()``# N row deletion in Matrix``res ``=` `[sub ``for` `sub ``in` `test_list ``if` `sub.count(N) !``=` `len``(sub)]`` ` `# print result``print``(``"The list after removal of N rows : "` `+` `str``(res))`

Output :

```The original list : [[1, 4, 2], [False, 9, 3], [6, 6, 6], [1, 0, 1]]
The list after removal of N rows : [[1, 4, 2], [False, 9, 3], [1, 0, 1]]
```

Method #2 : Using list comprehension + `set()`
This particular task can also be performed by converting the entire row into a set and then checking for the single value N set for equality and removing if a match is found.

 `# Python3 code to demonstrate``# N row deletion in Matrix``# using list comprehension + set()`` ` `# initializing matrix``test_list ``=` `[[``1``, ``4``, ``2``], [``False``, ``9``, ``3``],``            ``[``6``, ``6``, ``6``], [``1``, ``0``, ``1``]]`` ` `# printing original list``print``(``"The original list : "` `+` `str``(test_list))`` ` `# initializing N ``N ``=` `6`` ` `# using list comprehension + set()``# N row deletion in Matrix``res ``=` `[sub ``for` `sub ``in` `test_list ``if` `set``(sub) !``=` `{N}]`` ` `# print result``print``(``"The list after removal of N rows : "` `+` `str``(res))`

Output :

```The original list : [[1, 4, 2], [False, 9, 3], [6, 6, 6], [1, 0, 1]]
The list after removal of N rows : [[1, 4, 2], [False, 9, 3], [1, 0, 1]]
```

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