Feature or enhancement

Proposal:

More discussion:#132504 (comment)

This is the current message which is not very clear (it comes fromctypes.sizeof):

>>>frommultiprocessingimportArray>>>Array('x',1)...TypeError:this typehasnosize

I propose we change it to:

>>>frommultiprocessingimportArray>>>Array('x',1)TypeError:badtypecode (mustbeactypestypeoroneofc,b,B,u,h,H,i,I,l,L,q,Q,ford)

This is modeled after the error message inarray.array which is more informative:

>>>array('x')...ValueError:badtypecode (mustbeb,B,u,w,h,H,i,I,l,L,q,Q,ford)

(AValueError seems like a more appropriate option for multiprocessing as well, but that'd be a breaking change)
Note that,multiprocessing.Array (andValue) does not support the 'w' typecode whilearray.array does.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

#132504 (comment)

Linked PRs

• gh-133017: Improve error message for invalid typecodes inmultiprocessing.{Array,Value} #133252