Template run.py uses typing but fails mypy

[deepyaman]

Description

There are typing issues in template run.py; e.g. runner is typed as a str but later used as a Runner.

Some of the issues may just require bypassing (e.g. Pathlib / operator).

Context

I'm trying to check typing in my project.

Steps to Reproduce

1. Create a new kedro project.
2. Install mypy.
3. Run mypy. My mypy.ini:

[mypy]
new_semantic_analyzer = True

[mypy-kedro.*,nbstripout,numpy,pandas,pytest,scipy.*]
ignore_missing_imports = True

Expected Result

No errors.

Actual Result

I have to add:

[mypy-cotopaxi.run]
ignore_errors = True

to mypy.ini, else:

(project-cotopaxi) BOS-178551-C02X31K9JHD4:project-cotopaxi deepyaman$ mypy src/cotopaxi src/tests kedro_cli.py 
src/cotopaxi/run.py:80: error: Incompatible types in assignment (expression has type "Path", variable has type "str")
src/cotopaxi/run.py:83: error: Unsupported left operand type for / ("str")
src/cotopaxi/run.py:84: error: Unsupported left operand type for / ("str")
src/cotopaxi/run.py:147: error: "str" not callable
src/cotopaxi/run.py:147: error: "None" not callable

Your Environment

Include as many relevant details about the environment in which you experienced the bug:

• Kedro version used (pip show kedro or kedro -V): 0.13.1.dev53 🤣
• Python version used (python -V): 3.7.3
• Operating system and version:

[tolomea]

We recommend enabling the mypy flag --allow-redefinition and we use it internally and it will probably become the default in a future mypy version.
https://mypy.readthedocs.io/en/latest/common_issues.html#redefinitions-with-incompatible-types
https://mypy.readthedocs.io/en/latest/command_line.html?highlight=redefinition#miscellaneous-strictness-flags

Does that resolve your issue?

On a larger note we are considering options around linting the template to prevent issues with things like mypy.

[deepyaman]

@tolomea That works, thanks!