class Product(Struct):
# Product name of 20 bytes.
name = Str(20)
# Product quantity (0 to 255).
# default: signed=False
quantity = Int(1)
# Weight in Kilogram (Kg) (0 to 167,772,15)
weight = Int(3)
# volume in liters (L) (0 to 65,536)
volume = Int(2)
# Unite volume and weight fields and share same memory space.
# Then, total will be 3 bytes instead of 5 bytes.
__unions__ = [('volume', 'weight')]
class Person(Struct):
# String name of 15 bytes.
name = Str(20)
# Gender of 1 byte (Char)
gender = Char()
# Age integer of 1 byte (0 to 255)
age = Int(1)
# Integer money of 8 bytes (-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807)
money = Int(8, signed=True)
# 1 bit boolean fields (total: 1 byte)
# default: Bool(1, bits=True)
is_extroverted = Bool()
works_remotely = Bool()
is_vegetarian = Bool()
exercises_regularly = Bool()
has_driver_license = Bool()
enjoys_cooking = Bool()
has_pets = Bool()
likes_to_travel = Bool()
shopping_cart = Product[None]
class Family(Struct):
# Store a Person struct for mother.
mother = Person
# Store a Person struct for father.
father = Person
# Unlimited childrens.
# (This is only possible because it is the last field
# of the struct, otherwise the number of items must be specified)
children = Person[None]
class PNG(Struct):
signature = Constant(b'\x89PNG\r\n\x1a\n')
...
