Question

I have two arrays: array and least_common (filter array)

The following code iterates through array, checks for elements that match least_common, and if finds it, modifies it and appends it to a new array.

 for i in range (len(array)):
        for j in range(len(least_common)):
            if array[i] is least_common[j][0]:                
                new_array.append ((array[i]) + (array[i] * (mod[1]/100)))

However, if the element in array does not match any of the elements in least_common I wan’t to append it to new_array, then iterate to the next element in array to begin the checking process again.

Answer 1

This code is a bit wonky to me — I think you want to start with something more like:

lookup = set([x[0] for x in least_common])
new_array = []
for elem in array:
    if elem in lookup:
        new_array.append(elem + (elem * (mod[1]/100)))
    else:
        new_array.append(elem)