searching for strings (in a tuple) in a string

[manstey]

Hi,

I often use:

a='yy'
tup=('x','yy','asd')
if a in tup:
   <...>

but I can't find an equivalent code for:

a='xfsdfyysd asd x'
tup=('x','yy','asd')
if tup in a:
   < ...>

I can only do:

if 'x' in a or 'yy' in a or 'asd' in a:
   <...>

but then I can't make the if clause dependent on changing value of tup.

Is there a way around this?