# Python – Elements Product till K value

• Last Updated : 27 Feb, 2020

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
```

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