Sometimes, while working with Python lists, we can have a problem in which we need to check for a Matrix. This type of problem can have a possible application in Data Science domain due to extensive usage of Matrix. Let’s discuss a technique and shorthand which can be used to perform this task.
Method : Using isinstance() + all()
This problem can be performed using the combination of above functions. The all() can be used to check for all the elements of list and isinstance function checks for the list datatype in list. The logic behind is, every element of list must be a list to qualify it as matrix.
Python3
# Python3 code to demonstrate working of# Check if list is Matrix# using isinstance() + all()# initialize liststest_list = [[4, 5], [5, 8], [9, 10]]# printing original listprint("The original list is : " + str(test_list))# Check if list is Matrix# using isinstance() + all()res = all(isinstance(ele, list) for ele in test_list)# printing resultprint("Is list a Matrix ?: " + str(res)) |
The original list is : [[4, 5], [5, 8], [9, 10]] Is list a Matrix ?: True
Time Complexity: O(n), where n is the length of the list test_list
Auxiliary Space: O(1) constant additional space is needed
Method #2: Using filter()+isinstance() + lambda functions
Python3
# Python3 code to demonstrate working of# Check if list is Matrix# initialize liststest_list = [[4, 5], [5, 8], [9, 10]]# printing original listprint("The original list is : " + str(test_list))# Check if list is Matrix# using isinstance() + all()res = list(filter(lambda x: isinstance(x, list), test_list))if(len(res) == len(test_list)): res = Trueelse: res = False# printing resultprint("Is list a Matrix ?: " + str(res)) |
The original list is : [[4, 5], [5, 8], [9, 10]] Is list a Matrix ?: True
Time Complexity:O(N)
Auxiliary Space: O(N)
Method3: Using the type()+all() function:
Use the type() function to check if all elements of the list are of type list. Time complexity of this approach would be O(n) and space complexity would be O(1)
Python3
# initialize listtest_list = [[4, 5], [5, 8], [9, 10]]# printing original listprint("The original list is : " + str(test_list))# Check if list is Matrix using type() functionres = all(type(i) is list for i in test_list)# printing resultprint("Is list a Matrix ?: " + str(res))#This code is contributed by Edula Vinay Kumar Reddy |
The original list is : [[4, 5], [5, 8], [9, 10]] Is list a Matrix ?: True
This approach uses the type() function to check if all elements of the list are of type list.
Time complexity: O(n)
Auxiliary space: O(1).
