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0 pointspansa25y ago0 comments

> bool(Array(False, False)) would evaluate to True

Isn't that consistent with the built-in `list`, though, because `bool([False, False])` is True?

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2 comments · 1 top-level

lauriat5y ago· 1 in thread

My explanation was pretty poor, let me rephrase

For example, when calling

  Array((x, y), (z, w)).index((z, w))

the following piece of code is executed

  bool(Array((x, y)).__eq__((z, w)))
  = bool(Array(False, False))

If __bool__ returned whether the Array is nonempty, bool(Array(False, False)) would evaluate to True and the method would wrongly return 0.

You're right that it would be more clear if __bool__ would behave similarly, but since Array computes operations element-wise, it isn't possible.

wodenokoto5y ago

I think the complaint is that you are using `bool` as a `all()` call on your Arrays.

If you used `all()` in your implementation instead, you could be compatible with the idiomatic use of `bool(my_list)` and the _very_ common `if my_list:` structure could be used with Arrays too (like most people probably would expect from a "better list type")

Regardless, Pandas struggles with the same problem, so you are at least in good company :)

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