从 function 返回大量变量的优雅方式

Question

I have a python method of a class which is calculating a bunch of stuff, stores them in 8 different variables and then want to return these values.

Something on the lines;

def rate_lookup(self, a):
   ....
   ....

   return(charge, 
              handling_charge,
              delivery_charge,
              fuel_surcharge,
              overheight_surcharge,
              security_charge,
              documentation_fee,
              unpacking_removal_fee)

Problem is I would then have to save these return values in anothe similar set of variables on the function call. That doesn't look very elegant and uses a lot of variables.

I do need each variables value as I need to later print them out to console based on certain criteria.

Whats the best way to retun a lot of variables value.

Answer 1

IMO, this usually means your function is doing too much you might want to break it down to several functions or a Class. if you still decide you want to use a single function, I'd suggest using a namedtuple to return you values in a manner you could refer to them by name.

Answer 2

You need a dataclass. Pick one which suits best for you:

• dataclasses.dataclass (python 3.7+)
• typing.NamedTuple (python 3.6+)
• collections.namedtuple (any python, no typing support)
• attrs (any python, supports typing, more powerful that everything above, but third-party)
• Just a custom class with__slots__