3.7. Type Annotation NamedTuple¶
3.7.1. SetUp¶
>>> from typing import NamedTuple
3.7.2. Problem¶
>>> def hello_astronaut(astronaut):
... result = f'Hello {astronaut[0]} {astronaut[1]}'
>>> mark = ('Mark', 'Watney', 40)
>>> hello_astronaut(mark)
>>> iris = ('Iris', 'Setosa')
>>> hello_astronaut(iris)
3.7.3. Solution 1 - tuple¶
>>> def hello_astronaut(astronaut: tuple[str,str,int]):
... result = f'Hello {astronaut[0]} {astronaut[1]}'
>>> mark = ('Mark', 'Watney', 40)
>>> hello_astronaut(mark) # ok
>>> iris = ('Iris', 'Setosa')
>>> hello_astronaut(iris) # error (missing int)
>>> iris = ('Iris', 'Setosa', 1)
>>> hello_astronaut(iris) # ok
3.7.4. Solution 2 - NamedTuple¶
>>> class Astronaut(NamedTuple):
... firstname: str
... lastname: str
... age: int
>>>
>>>
>>> def hello_astronaut(astronaut: Astronaut):
... result = f'Hello {astronaut[0]} {astronaut[1]}'
>>> mark = Astronaut('Mark', 'Watney', 40)
>>> hello_astronaut(mark) # ok
>>> mark = Astronaut(firstname='Mark', lastname='Watney', age=40)
>>> hello_astronaut(mark) # ok
>>> iris = ('Iris', 'Setosa', 1)
>>> hello_astronaut(iris) # ok
3.7.5. Attributes¶
Using NamedTuple we can also make hello_astronaut() function
more readable by using attributes astronaut.firstname and
astronaut.lastname instead of indexes, such as: astronaut[0]
and astronaut[1].
>>> def hello_astronaut(astronaut: Astronaut):
... result = f'Hello {astronaut.firstname} {astronaut.lastname}'
3.7.6. IsInstance¶
Note, that NamedTuple is still a tuple and you can compare both!
>>> class Astronaut(NamedTuple):
... firstname: str
... lastname: str
>>> a = ('Mark', 'Watney')
>>> b: Astronaut = ('Mark', 'Watney')
>>> c = Astronaut('Mark', 'Watney')
>>> d = Astronaut(firstname='Mark', lastname='Watney')
>>> isinstance(a, tuple)
True
>>>
>>> isinstance(b, tuple)
True
>>>
>>> isinstance(c, tuple)
True
>>>
>>> isinstance(d, tuple)
True
>>> type(a)
<class 'tuple'>
>>> type(b)
<class 'tuple'>
>>> type(c)
<class '__main__.Astronaut'>
>>> type(d)
<class '__main__.Astronaut'>
>>> Astronaut.mro()
[<class '__main__.Astronaut'>, <class 'tuple'>, <class 'object'>]
>>> a == b
True
>>> b == c
True
>>> c == d
True
3.7.7. Size¶
>>> from sys import getsizeof
>>>
>>> getsizeof(a)
56
>>> getsizeof(b)
56
>>> getsizeof(c)
56
>>> getsizeof(d)
56
3.7.8. NamedTuple¶
SetUp:
>>> from typing import NamedTuple
Problem:
>>> def hello_astronaut(astronaut):
... result = f'Hello {astronaut[0]} {astronaut[1]}'
>>>
>>>
>>> mark = ('Mark', 'Watney', 40)
>>> hello_astronaut(mark)
>>>
>>> iris = ('Iris', 'Setosa')
>>> hello_astronaut(iris)
Solution 1 - tuple:
>>> def hello_astronaut(astronaut: tuple[str,str,int]):
... result = f'Hello {astronaut[0]} {astronaut[1]}'
>>>
>>>
>>> mark = ('Mark', 'Watney', 40)
>>> hello_astronaut(mark) # ok
>>>
>>> iris = ('Iris', 'Setosa')
>>> hello_astronaut(iris) # error (missing int)
>>>
>>> iris = ('Iris', 'Setosa', 1)
>>> hello_astronaut(iris) # ok
Solution 2 - NamedTuple:
>>> class Astronaut(NamedTuple):
... firstname: str
... lastname: str
... age: int
>>>
>>>
>>> def hello_astronaut(astronaut: Astronaut):
... result = f'Hello {astronaut[0]} {astronaut[1]}'
>>>
>>>
>>> mark = Astronaut('Mark', 'Watney', 40)
>>> hello_astronaut(mark) # ok
>>>
>>> mark = Astronaut(firstname='Mark', lastname='Watney', age=40)
>>> hello_astronaut(mark) # ok
>>>
>>> iris = ('Iris', 'Setosa', 1)
>>> hello_astronaut(iris) # ok
Using NamedTuple we can also make hello_astronaut() function
more readable by using attributes astronaut.firstname and
astronaut.lastname instead of indexes, such as: astronaut[0]
and astronaut[1].
>>> def hello_astronaut(astronaut: Astronaut):
... result = f'Hello {astronaut.firstname} {astronaut.lastname}'
Note, that NamedTuple is still a tuple and you can compare both!
>>> class Astronaut(NamedTuple):
... firstname: str
... lastname: str
>>> a = ('Mark', 'Watney')
>>> b: Astronaut = ('Mark', 'Watney')
>>> c = Astronaut('Mark', 'Watney')
>>> d = Astronaut(firstname='Mark', lastname='Watney')
>>> isinstance(a, tuple)
True
>>>
>>> isinstance(b, tuple)
True
>>>
>>> isinstance(c, tuple)
True
>>>
>>> isinstance(d, tuple)
True
>>> type(a)
<class 'tuple'>
>>> type(b)
<class 'tuple'>
>>> type(c)
<class '__main__.Astronaut'>
>>> type(d)
<class '__main__.Astronaut'>
>>> Astronaut.mro()
[<class '__main__.Astronaut'>, <class 'tuple'>, <class 'object'>]
>>> a == b
True
>>> b == c
True
>>> c == d
True
>>> from sys import getsizeof
>>>
>>> getsizeof(a)
56
>>> getsizeof(b)
56
>>> getsizeof(c)
56
>>> getsizeof(d)
56
#%%
- class Person(NamedTuple):
firstname: str lastname: str
- def say_hello(person: Person):
print(f'Witaj {person.firstname} {person.lastname}')
osoba = Person(firstname='Mark', lastname='Watney') say_hello(osoba)
#%%
- class Point(TypedDict):
x: int y: int z: int
point = Point(x=1, y=2, z=3) point: Point = {'x':1, 'y':2, 'z':3} point: Point = {'x':1, 'y':2, 'z':3.0} # z jest float, a miał być int point: Point = {'x':1, 'y':2} # brakuje z
- class Point(TypedDict):
x: int y: int z: int | None
point: Point = {'x':1, 'y':2, 'z':None}
- class Point(TypedDict):
x: int y: int z: NotRequired[int]
point: Point = {'x':1, 'y':2, 'z':3} # ok point: Point = {'x':1, 'y':2, 'z':3.0} # nie ok point: Point = {'x':1, 'y':2, 'z':None} # nie ok point: Point = {'x':1, 'y':2} # ok
- class Point(TypedDict):
x: Required[int] y: Required[int] z: NotRequired[int]
- class GeographicCoordinate(NamedTuple):
latitude: float longitude: float
- locations: list[GeographicCoordinate] = [
(25.91375, -60.15503), (-11.01983, -166.48477), (-11.01983, -166.48477)]
- locations: list[GeographicCoordinate] = [
GeographicCoordinate(25.91375, -60.15503), GeographicCoordinate(-11.01983, -166.48477), GeographicCoordinate(-11.01983, -166.48477)]
- locations: list[GeographicCoordinate] = [
GeographicCoordinate(latitude=25.91375, longitude=-60.15503), GeographicCoordinate(latitude=-11.01983, longitude=-166.48477), GeographicCoordinate(latitude=-11.01983, longitude=-166.48477)]
3.7.9. Further Reading¶
More information in Type Annotations
More information in CI/CD Type Checking