# The __coerce__ method

**__coerce__**(self, other)

Called to implement mixed-mode

numeric arithmetic. Should either
return a 2-tuple containing self and other converted to a common
numeric type, or **None** if conversion is impossible. When the common
type would be the type of `other`

, it is sufficient to return **None**,
since the interpreter will also ask the other object to attempt a
coercion (but sometimes, if the implementation of the other type
cannot be changed, it is useful to do the conversion to the other type
here). A return value of **NotImplemented** is equivalent to returning
**None**.