python - How to delete something from a list?

I am trying to write a Suduoku game. Every time I use a
number, I need to delete it from the list.

I
have already tried .pop[1], but it did nothing when the number
was one.

import
            random


rownum1 =
            ["1","2","3","4","5","6","7","8","9"]
print(random.choice(rownum1))

if
            random.choice(rownum1) == "1":
 del rownum1[0]

            print(rownum1)

If one
is randomly selected I expect the output to
be:

["2","3","4","5","6","7","8","9"]

But
nothing is happening when one is randomly chose.