Sequence

String together Assert and Modify annotations.

Basic example

The example

from typing_exe.annotations import Sequence, Assert, Modify
from typing_exe.decorators import execute_annotations, cleanup_annotations


@cleanup_annotations
@execute_annotations
def foo(
        a: Sequence[
            int,
            Assert[lambda a: type(a) is int, lambda a: a != 0],
            Modify[lambda a: abs(a)],
            Assert[lambda a: a > 5]
        ]
):
    ...

Explanation

When foo gets executed, the following will happen:

1. The first Assert will check a's type, then check that it is not zero
2. The Modify will then return the absolute value of a
3. The second Assert will check that a is now greater than five
4. The function-body will be executed

Description

The first entry to the Sequence.__getitem__-method can either be a typehint or an Assert or Modify. All other entries have to be either an Assert or a Modify.

Here are some legal calls to Sequence:

from typing_exe.annotations import Sequence, Assert, Modify


Sequence[int, Assert[...], Modify[...]]
Sequence[Assert[...], Modify[...]]
Sequence[Modify[...], Modify[...], Modify[...]]
Sequence[str, Modify[...]]
Sequence[Assert[...]]   # not very useful