Python Program that filters out non-empty rows of a matrix
Given Matrix, the following article shows how to filter all the Non-Empty rows of a matrix. In simpler terms, the codes provided below return a matrix after removing empty rows from it.
Input : test_list = [[4, 5, 6, 7], [], [], [9, 8, 1], []]
Output : [[4, 5, 6, 7], [9, 8, 1]]
Explanation : All empty rows are removed.
Input : test_list = [[4, 5, 6, 7], [], [9, 8, 1], []]
Output : [[4, 5, 6, 7], [9, 8, 1]]
Explanation : All empty rows are removed.Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.
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Method 1 : Using list comprehension and len()
In this we check each row for its length, if its length is greater than 0 then that row is added to result.
Python3
# initializing listtest_list = [[4, 5, 6, 7], [], [], [9, 8, 1], []] # printing original listsprint("The original list is : " + str(test_list)) # checking for row lengths using len()res = [row for row in test_list if len(row) > 0] # printing resultprint("Filtered Matrix " + str(res)) |
Output:
The original list is : [[4, 5, 6, 7], [], [], [9, 8, 1], []]
Filtered Matrix [[4, 5, 6, 7], [9, 8, 1]]
Method 2 : Using filter(), lambda and len()
In this, we filter rows w.r.t lengths using filter() and lambda function. The len() is used to get the length.
Python3
# initializing listtest_list = [[4, 5, 6, 7], [], [], [9, 8, 1], []] # printing original listsprint("The original list is : " + str(test_list)) # checking for row lengths using len()# filtering using filter() + lambdares = list(filter(lambda row: len(row) > 0, test_list)) # printing resultprint("Filtered Matrix " + str(res)) |
Output:
The original list is : [[4, 5, 6, 7], [], [], [9, 8, 1], []]
Filtered Matrix [[4, 5, 6, 7], [9, 8, 1]]
