Mypy- Report Generation for only specified files

Question

I'm looking at the doc here:

Is there a way to ignore certain files when making a report? I'm seeing some files I don't want a report of, and I'm wondering if I can make a runtime configuration or somthing to ignore them.

Answer 1

Yes.

You can ignore a whole package (cf this question and the relevant Github issue).

Ignoring just a file was discussed in this GitHub issue which recommended other ways to achieve the same result (@no_type_check decorator for functions, checking the Python version, custom mypy call script, ...) and was closed as a duplicate of this other issue which happens to have been closed 13 days ago (2021-06-10) by Guido because "it didn't seem all that important", although the PEP 484 states :

A # type: ignore comment on a line by itself at the top of a file, before any docstrings, imports, or other executable code, silences all errors in the file.

In another related GitHub issue, someone mentions there is a command option for exactly that since version 0.810 (2021-02-10) : --exclude (cf commit)

A regular expression that matches file names, directory names and paths which mypy should ignore while recursively discovering files to check. Use forward slashes on all platforms.

Here is my setup :

# file: ok.py
a: int = 4

# file: bad.py
a: int = "definitively not an integer"

• with MyPy v0.800 :

  $ mypy . --txt-report report0800; cat report0800/index.txt
  bad.py:2: error: Incompatible types in assignment (expression has type "str", variable has type "int")
  Generated TXT report (via XSLT): /home/stack_overflow/PyCharmProjects/68071098/report0800/index.txt
  Found 1 error in 1 file (checked 2 source files)
  Mypy Type Check Coverage Summary
  ================================
  
  Script: index
  
  +-----+-------------------+-------+
  | Module | Imprecision       | Lines |
  +-----+-------------------+-------+
  | bad |   0.00% imprecise | 2 LOC |
  | ok  |   0.00% imprecise | 2 LOC |
  +-----+-------------------+-------+
  | Total |   0.00% imprecise | 4 LOC |
  +-----+-------------------+-------+
  

• with MyPy v0.812 :

  $ mypy . --txt-report report0812 --exclude 'bad.py'; cat report0812/index.txt
  Generated TXT report (via XSLT): /home/stack_overflow/PyCharmProjects/68071098/report0812/index.txt
  Success: no issues found in 1 source file
  Mypy Type Check Coverage Summary
  ================================
  
  Script: index
  
  +----+-------------------+-------+
  | Module | Imprecision       | Lines |
  +----+-------------------+-------+
  | ok |   0.00% imprecise | 2 LOC |
  +----+-------------------+-------+
  | Total |   0.00% imprecise | 2 LOC |
  +----+-------------------+-------+
  

I tried on a real project and the regex behaviour seemed finicky (or maybe I did not understood well the docs), but it worked nonetheless.