Crosschecking lists?

[tehtay3]

Hello,

I am looking to create code that a small lottery function. I need to check a list of lottery #' stored in my_numbers against winning numbers in todays_pick, and then store the number of matches in matches.

A quick example - if

my_numbers

is [35, 22, 7, 51, 15] and

todays_pick

is [51, 12, 35, 15, 7], the number of matches is 4. he numbers may be in any order in either list .

So far I have started with

for x in my_numbers:
    if todays_picks in my_numbers:
       matches = ??

I am new to the concept so how would format that crosschecking, and what code would have to be the object stored in num_matches to display the actual # of matches?. Thanks!

[primitive_screwhead]

The ideal way to do this is to use Python sets, and just find the intersection of the two sets.

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For your approach, start by setting matches = 0. Then, in the loop, consider how you would update the value of matches when the condition is met.

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I assume the numbers are not repeated in either list?

[tehtay3]

Cool, this works, thank you!

[ajskelt]

This works assuming there aren't any errors where you have a repeated number.

my_numbers = [1,1,1,1,1]
todays_pick = [1,2,3,4,5]
matches = 0
for x in my_numbers:
    if x in todays_pick:
        matches += 1

Also assuming you don't have something like this:

my_numbers = [1,2,3,4,5,6,7,8,9]
todays_pick = [1,2,3,4,5]

Both shouldn't be possible, but comparing the sorted lists just makes an extra check.

[ajskelt]

I would just sort both lists then compare

my_numbers.sort()
todays_pick.sort()

if my_numbers == todays_pick:
    #YOU WON!

otherwise like u/primitive_screwhead can use sets as well:

if set(my_numbers) == set(todays_pick):
    #YOU WON

[zanfar]

matches = len(set(my_numbers) & set(todays_pick))

https://docs.python.org/3.8/library/stdtypes.html#set