Basics

Mapping DAML types to Python types

DAML type	Python type
Unit or ()	dict() (an empty dictionary)
Bool	bool
Integer or Int	int
Decimal	decimal.Decimal
Text	str
Party	str
RelTime	datetime.timedelta
Date	datetime.datetime
Time	datetime.time
ContractId a	dazl.model.core.ContractId
List a	list
records	dict where keys are field names and values are as listed in this table
variants	dict containing a single key naming the specific constructor to use, and value as listed in this table

Some examples

The examples below are valid for the following DAML:

data Rectangle = Rectangle with
    length: Decimal
    width: Decimal

data Expr a = Num a
            | Product (Expr a) (Expr a)
            | Sum (Expr a) (Expr a)

template CalculateRequest
  with
    requester: Party
    computer: Party
    expression: Expr Decimal

template CalculateResponse
  with
    requester: Party
    computer: Party
    value: Decimal