如果用户输入中包含str（'a'）或str（'b'）或str（'c'），则执行某些操作

Question

I would like to put multiple strings for one in statement one one line:

input = str(raw_input(''))   
if str('a') or ('b') or ('c') in str(input):
    print "a string"
else:
    print "no"

Is it possible to have multiple strings for a single in statement?

Answer 1

First of all str('a') == 'a' (because 'a' is already a string), so you can leave that out.

'a' or 'b' or 'c' in input

This expression is parsed as the following:

('a') or ('b') or ('c' in input)

So you are checking if 'a' or 'b' evalute to true, which is the case. If you want to check them all using the in operator, you have to explicitely specify that:

'a' in input or 'b' in input or 'c' in input

You can also simplify that then:

any(x in input for x in ('a', 'b', 'c'))

Answer 2

It is, but what you wrote does something entirely different. It checks to see if str('a') is truthy, if 'b' is truthy, or if 'c' is in input . While Python is very readable, it doesn't make assumptions about what you write. You have to be explicit:

if 'a' in input or 'b' in input or 'c' in input:
    ...

Or:

strings = ('a', 'b', 'c')

if any(s in input for s in strings):
    ...

Calling str() with a string argument is pointless. Also, input is the name of a builtin, so I suggest you rename your variable.