Python – Sort row by K multiples

When sorting rows based on the count of multiples of K, we can use a custom key function with list comprehension and the modulus operator. This approach counts how many elements in each row are divisible by K and sorts accordingly.

Example

Let's sort a list of sublists based on how many multiples of K each sublist contains ?

def multiple_sort_val(row):
    return len([ele for ele in row if ele % K == 0])

my_list = [[11, 44, 7, 11], [7, 5, 44, 11], [11, 6, 35, 44], [92, 92, 5]]

print("The list is:")
print(my_list)

K = 11
print("The value for K is:")
print(K)

my_list.sort(key=multiple_sort_val)

print("The resultant list is:")
print(my_list)

The list is:
[[11, 44, 7, 11], [7, 5, 44, 11], [11, 6, 35, 44], [92, 92, 5]]
The value for K is:
11
The resultant list is:
[[92, 92, 5], [7, 5, 44, 11], [11, 6, 35, 44], [11, 44, 7, 11]]

How It Works

The sorting process works as follows:

• The multiple_sort_val function counts elements divisible by K in each row using ele % K == 0

• Row [92, 92, 5] has 0 multiples of 11, so it comes first

• Row [7, 5, 44, 11] has 1 multiple of 11 (the number 11)

• Row [11, 6, 35, 44] has 1 multiple of 11 (the number 11)

• Row [11, 44, 7, 11] has 2 multiples of 11 (both 11s), so it comes last

Using Lambda Function

You can also use a lambda function for more concise code ?

my_list = [[11, 44, 7, 11], [7, 5, 44, 11], [11, 6, 35, 44], [92, 92, 5]]
K = 11

# Sort using lambda function
my_list.sort(key=lambda row: len([ele for ele in row if ele % K == 0]))

print("Sorted list:")
print(my_list)

Sorted list:
[[92, 92, 5], [7, 5, 44, 11], [11, 6, 35, 44], [11, 44, 7, 11]]

Conclusion

Sorting by K multiples uses a custom key function that counts divisible elements in each row. The sort() method with a key parameter arranges rows in ascending order based on the count of multiples.