how to construct a list of only one tuple

[TP]

bearophileHUGS at lycos.com wrote:

>> >>> a=("1","2")
>> >>> b=[("3","4"),("5","6")]
>> >>> list(a)+b
>> ['1', '2', ('3', '4'), ('5', '6')]
> 
>>>> a = ("1", "2")
>>>> b = [("3", "4"), ("5", "6")]
>>>> [a] + b
> [('1', '2'), ('3', '4'), ('5', '6')]

Thanks a lot.
Why this difference of behavior between list(a) and [a]?

Julien

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