If valst is a True list (containing elements), why does this work:
valst.append(seq)
id_seq_dict[id] = valst
But this does not work:
id_seq_dict[id] = valst.append(seq)
Is it because the append method returns nothing?
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Benj
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The append method returns `None`. – Martijn Pieters Sep 25 '15 at 20:46
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Yes. that is correct – dsh Sep 25 '15 at 20:46
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Exactly. `append()` returns `None` as well as `extend()` which I think is what you should have used here because you are appending a list to another list. Maybe you might want to `id_seq_dict[id] = valst + seq` but this won't mutate `valst` – Ozgur Vatansever Sep 25 '15 at 20:47
