Python – Elements Product till K value

One of the problem that is basically a subproblem for many complex problems, finding product number till a certain number in list in python, is commonly encountered and this particular article discusses possible solutions to this particular problem.

Method #1 : Naive method
The most common way this problem can be solved is using a loop and just multiplying the occurrences of elements that are till given number K.

# Python 3 code to demonstrate
# Elements Product till K value
# using naive method

# initializing list
test_list = [1, 7, 5, 6, 3, 8]

# initializing k
k = 6

# printing list
print ("The list : " + str(test_list))

# using naive method
# Elements Product till K value
res = 1
for i in test_list :
    if i <= k :
        res *= i

# printing the product
print ("The product till K : " + str(res))

Output :

The list : [1, 7, 5, 6, 3, 8]
The product till K : 90

Method #2 : Using list comprehension
This method achieves this task in a similar way, but in a more concise manner. List comprehension always lowers the lines of codes in the program even though runs a similar approach in the background.

# Python 3 code to demonstrate
# Elements Product till K value
# using list comprehension

# getting Product
def prod(val) :
    res = 1
    for ele in val:
        res *= ele
    return res

# initializing list
test_list = [1, 7, 5, 6, 3, 8]

# initializing k
k = 6

# printing list
print ("The list : " + str(test_list))

# using list comprehension
# Elements Product till K value
res = prod([i for i in test_list if i <= k])

# printing the intersection
print ("The product till K : " + str(res))

Output :

The list : [1, 7, 5, 6, 3, 8]
The product till K : 90