What's the best practice for handling single-value tuples in Python?

Question

I am using a 3rd party library function which reads a set of keywords from a file, and is supposed to return a tuple of values. It does this correctly as long as there are at le

Answer 1

For your first problem, I'm not really sure if this is the best answer, but I think you need to check yourself whether the returned value is a string or tuple and act accordingly.

As for your second problem, any variable can be turned into a single valued tuple by placing a , next to it:

>>> x='abc'
>>> x
'abc'
>>> tpl=x,
>>> tpl
('abc',)

Putting these two ideas together:

>>> def make_tuple(k):
...     if isinstance(k,tuple):
...             return k
...     else:
...             return k,
... 
>>> make_tuple('xyz')
('xyz',)
>>> make_tuple(('abc','xyz'))
('abc', 'xyz')

Note: IMHO it is generally a bad idea to use isinstance, or any other form of logic that needs to check the type of an object at runtime. But for this problem I don't see any way around it.