Question

I’d like to determine if a string can be created using only characters in a list. For example,

>>>acceptableChars = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i']
>>>print isAcceptable("abc")
True
>>>print isAcceptable("xyz")
False

Answer 1

Make a set from acceptableChars:

>>> acceptableChars = set('abcdefghi')

Now we can make isAcceptable check if any of the characters in its argument are not in acceptableChars using set subtraction:

>>> def isAcceptable(s):
    return set(s) <= acceptableChars
>>> isAcceptable("abc")
True
>>> isAcceptable("xyz")
False