[Solved] Where is the difference?

Question

Sorry, if this is a newbie question but why does this code work:

import string
astring=str(input())
for i in astring:
if i not in string.ascii_letters and i not in string.digits and i != " ":
#Do something

.. and this code not:

import string
astring=str(input())
for i in astring:
if i not in [string.ascii_letters, string.digits, " "]:
#Do something

Any suggestions how to shorten the task more?

Answer 1

You need to concatenate the lists.

For example,

list1 + list2 + list3

Answer 2

so easy, thank you ..
it is really an easy way:

for i in astring:
if i not in (string.ascii_letters + string.digits + " "):