typingiterable
typingiterable is a simple python package for the actual typing of each element of an iterable with type hint notation.
Install
pip install git+ssh://git@github.com/osoken/typingiterable.git
Features and Examples
Actual Typing with Type Hint Notation
The following example shows how the main component typingiterable.TypingIterable works:
from dataclasses import dataclass
from typingiterable import TypingIterable
@dataclass
class User:
id: int
name: str
raw_data = [{"id": 0, "name": "Alice"}, {"id": 1, "name": "Bob"}]
for d in TypingIterable[User](raw_data):
assert isinstance(d, User)It is equivalent to write:
from dataclasses import dataclass
from typingiterable import TypingIterable
@dataclass
class User:
id: int
name: str
raw_data = [{"id": 0, "name": "Alice"}, {"id": 1, "name": "Bob"}]
for d in (User(**d) for d in raw_data):
assert isinstance(d, User)Error Handling
typingiterable.TypingIterable also has the error handling feature.
from dataclasses import dataclass
from typingiterable import TypingIterable
from collections.abc import Mapping
from typing import Union
@dataclass
class User:
id: int
name: str
def error_handler(d: Mapping[int, Union[int, str]], i: int, e: Exception) -> None:
print(f"{i}th element `{d}` is invalid due to the following error: {e}")
raw_data = [{"id": 0, "name": "Alice"}, {"name": "lack of id"}, {"id": 1, "name": "Bob"}]
for d in TypingIterable[User](raw_data, on_error=error_handler):
assert isinstance(d, User)The above example prints the following string:
1th element `{'name': 'lack of id'}` is invalid due to the following error: User.__init__() missing 1 required positional argument: 'id'
and it doesn't stop iterating. The example is equivalent to write:
from dataclasses import dataclass
from typingiterable import TypingIterable
from collections.abc import Mapping
from typing import Union
@dataclass
class User:
id: int
name: str
raw_data = [{"id": 0, "name": "Alice"}, {"name": "lack of id"}, {"id": 1, "name": "Bob"}]
for i, raw_d in enumerate(raw_data):
try:
d = User(**raw_d)
except Exception as e:
print(f"{i}th element `{raw_d}` is invalid due to the following error: {e}")
assert isinstance(d, User)Automatic Unpacking Arguments
typingiterable.TypingIterable checks the signature and automatically unpacks the arguments.
For functions which takes multiple positional arguments or multiple keyword arguments, such as dataclass and pydantic.BaseModel, it unpacks just like the above example.
If the function is single-argument, no unpacking is done.
from typingiterable import TypingIterable
raw_data = ["1", "2", "3", "4"]
for d in TypingIterable[int](raw_data):
assert isinstance(d, int)
