[issue39641] concatenation of Tuples

[Steven D'Aprano]

Steven D'Aprano <steve+python at pearwood.info> added the comment:

[Bruce]
> but try this, and it will NOT work:
> 
> FatThing= [(5, 4, "First Place"),
>            (6, 6, "Fifer Place"),
>            (2, 2, "Slowr Place")]
> print(FatThing)  #this works
> 
> FFThing = FatThing + ('22', '32', '55')  #this causes an error!

That is correct, it should cause an error because you are trying to 
concatenate a list and a tuple. This is an easier way to show the same 
behaviour:

    [] + ()  # fails with TypeError

[Bruce]
> however if you change all the members to strings, it will work!!!

I'm afraid you are mistaken. It still fails, as it should.

py> FatThing = [("a", "b", "First Place"),
...             ("c", "d", "Fifer Place"),
...             ("e", "f", "Slowr Place")]
py> FFThing = FatThing + ('22', '32', '55')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: can only concatenate list (not "tuple") to list

Please take more care when trying to report what you think is a bug. 
Remember that Python is about 30 years old and there are tens or 
hundreds of thousands of people using it every single day. 99% of the 
time, anything you, or I, find that looks like a bug, is a bug in *our* 
code, not Python. Especially when it is something as basic and 
fundamental as tuple concatenation.

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue39641>
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