On Wednesday 16 February 2005 09:08 am, alex wrote:
> how can I check if a variable is a structure (i.e. a list)? For my
> special problem the variable is either a character string OR a list of
> character strings line ['word1', 'word2',...]
>
> So how can I test if a variable 'a' is either a single character string
> or a list?
The literally correct but actually wrong answer is:
if type(a) == type([]):
print "'a' is a duck"
But you probably shouldn't do that. You should probably just test to
see if the object is iterable --- does it have an __iter__ method?
Which might look like this:
if hasattr(a, '__iter__'):
print "'a' quacks like a duck"
That way your function will also work if a happens to be a tuple,
a dictionary, or a user-defined class instance which is happens to
be iterable.
Being "iterable" means that code like:
for i in a:
print "i=%s is an element of a" % repr(i)
works. Which is probably why you wanted to know, right?
Cheers,
Terry
--
--
Terry Hancock ( hancock at anansispaceworks.com )
Anansi Spaceworks http://www.anansispaceworks.com
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