When it is required to filter out non-empty rows from a matrix, a simple list comprehension along with the ‘len’ method can be used.
Below is a demonstration of the same −
Example
my_list = [[21, 52, 4, 74], [], [7, 8, 4, 1], [], []]
print("The list is :")
print(my_list)
my_result = [row for row in my_list if len(row) > 0]
print("The resultant list is :")
print(my_result)Output
The list is : [[21, 52, 4, 74], [], [7, 8, 4, 1], [], []] The resultant list is : [[21, 52, 4, 74], [7, 8, 4, 1]]
Explanation
A list of list with integers is defined and is displayed on the console.
The list is iterated over using list comprehension.
It checks if the length of an element is greater than 0 or not.
If yes, it is stored in the list.
Otherwise, it is ignored.
This is assigned to a variable.
This variable is displayed as output on the console.