[Tutor] Dictionary Comprehensions

[spir]

Lie Ryan <lie.1296 at gmail.com> dixit:

> note that:
>  >>> [(y, x) for y in list("khalid") for x in range(6)]  
> [('k', 0), ('k', 1), ('k', 2), ('k', 3), ('k', 4), ('k', 5), ('h', 0), 
> ('h', 1), ('h', 2), ('h', 3), ('h', 4), ('h', 5), ('a', 0), ('a', 1), 
> ('a', 2), ('a', 3), ('a', 4), ('a', 5), ('l', 0), ('l', 1), ('l', 2), 
> ('l', 3), ('l', 4), ('l', 5), ('i', 0), ('i', 1), ('i', 2), ('i', 3), 
> ('i', 4), ('i', 5), ('d', 0), ('d', 1), ('d', 2), ('d', 3), ('d', 4), 
> ('d', 5)]
> 
> and when that big list is turned into a dict it gives:
>  >>> dict(_)  
> {'a': 5, 'd': 5, 'i': 5, 'h': 5, 'k': 5, 'l': 5}

... because a dict holds a single value per key, so last value overrides previous ones.

Denis
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