PlasmaCalcs.tools.iterables.scalar_item

PlasmaCalcs.tools.iterables.scalar_item(arraylike)

returns the single item from arraylike. raise InputError if not possible.

if arraylike.ndim or .size exists:

return arraylike.item() if ndim==0 or size==1, else crash.

else:

return arraylike[0] if len(arraylike)==1, else crash.