The oandapyV20.types module contains the types representing the types that are used in the API-specs of OANDA, check developer.oanda.com. These types offer a convenient interface between Python types and the types used in the REST-API.

Take for instance the PriceValue type. It is the string representation of a float.

from oandapyV20.types import PriceValue

pv1 = PriceValue(122.345)
pv2 = PriceValue("122.345")
pv1.value == pv2.value

Regardless the value we instantiate it with, a float or a string, the PriceValue instance will allways be a string value.

The types also validate the values passed. Invalid values will raise an exception.