检查列表的元素是否可以被另一个列表的所有元素整除

Question

I have two lists:

s = [6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]
a = [2,6] 

I want to print all numbers of s list that are both divisible by a[0] and a[1].

In a case like this I would simply do:

for num in s:
    if num % a[0] == 0 and num % a[1] == 0:
        print(num)

But let's assume I don't know how long the list is. How can I get it right?

I've tried to figure this out for some time now, but I am stuck.

Answer 1

You can use the all function with a generator expression like this:

if all(num % i == 0 for i in a):

Answer 2

You can use a nested list-comp with all , eg:

s = [6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]
a = [2,6]
result = [x for x in s if all(x % y == 0 for y in a)]

Gives you:

[6, 12, 18, 24]

Answer 3

you could calculate the least common multiple of a first:

from math import gcd

a = [2, 6]
s = [6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]
lcm = a[0] * a[1] // gcd(a[0], a[1])
print(list(x for x in s if x % lcm == 0)
# [6, 12, 18, 24]

this may be more efficient if your a is longer than just 2 elements.

---

in order to get the LCM of a list of elements you could use lcm_lst as defined below:

from math import gcd

def lcm(a, b):
    return a * b // gcd(a, b)

def lcm_lst(a):
    l = a[0]
    for x in a[1:]:
        l = lcm(l, x)
    return l