Hello everyone, I’m getting a type error from a generator function which i do not understand. Here is a minimal example: import numba as nb @nb.njit("int64()") def generator_test(): for i in range(5): yield i print(list(generator_test())) Which will give you: numba.core.errors.Ty…

Thanks again @gmarkall & @nelson2005 ! Your answers pointed me in the right direction. Raising StopIteration after the for-loop, allowed me to use the type-Signature of an unsigned 32 bit integer! import numba as nb @nb.njit("uint32()") def generator_test(): for i in range(5): yield …

Your function returns None so Numba is complaining that you’ve specified the return type as an integer. Yielding and returning are not the same, and we don’t have a way to specify what type is yield in the signature, as far as I am aware. Try using "none()" for the signature instead. However, on a…

Thank you very much for your replies! @gmarkall since in pure Python a generator function like this has no return value, but is terminated with a StopIteration exception, I did not expect a return value here either. I want to use this function in another function in which I fill a large array base…

Thank you for your reply! If I do that, i get an empty list import numba as nb @nb.njit() def generator_test(): for i in range(5): yield i print(generator_test.nopython_signatures) prints []

Right, there’s no deduced signature until you call the function.

Of course, thank you! Now I’m even more confused! If I go to the original version without type signature and without StopIteration and look at the nopython_signatures after calling the function, I get exactly the same signature as with StopIteration Exception and defined type signature: import num…

The type signatures you see are those that have been compiled. If you provide a signature then the function will be compiled for the given signature immediately. If you don’t, then variants for each set of argument types are compiled at the time of each call with new argument types - see Eager Comp…

Numba generator function throws typing error

Numba Community Support

nelson2005 August 20, 2024, 12:50pm 3

Also you can let numba infer it and then print nopython_signatures to see what signature was inferred

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Function signature matches but still fails

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Numba generator function throws typing error

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