How can I tell if a python variable is a string or a list?

Question

I have a routine that takes a list of strings as a parameter, but I\'d like to support passing in a single string and converting it to a list of one string. For example:

Answer 1

def func(files):
    for f in files if not isinstance(files, basestring) else [files]:
        doSomethingWithFile(f)

func(['file1', 'file2', 'file3'])

func('file1')