String building using join

[Alex Willmer]

On Sunday, January 2, 2011 5:43:38 PM UTC, gervaz wrote:
> Sorry, but it does not work
> 
> >>> def prg3(l):
> ...     return "\n".join([x for x in l if x])
> ...
> >>> prg3(t)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "<stdin>", line 2, in prg3
> TypeError: sequence item 0: expected str instance, Test found

def prg3(l):
    return '\n'.join([str(x) for x in l if x])

That should do it