Setup Mypy check at CI step

.travis.yml

@@ -51,11 +51,12 @@ jobs:
     - stage: Lint check
       python: "3.7"
       before_install: # Nothing to do
-      install: pip install flake8 "black==19.10b0" "isort==4.3.21"
+      install: pip install flake8 "black==19.10b0" "isort==4.3.21" "mypy==0.782"
       script:
         - flake8 .
         - black --check .
         - isort -rc -c .
+        - mypy --config-file mypy.ini
       after_success: # Nothing to do
 
     # GitHub Pages Deployment: https://docs.travis-ci.com/user/deployment/pages/

CONTRIBUTING.md

@@ -37,7 +37,7 @@ git clone https://github.com/pytorch/ignite.git
 cd ignite
 python setup.py develop
 pip install -r requirements-dev.txt
-pip install flake8 "black==19.10b0" "isort==4.3.21"
+pip install flake8 "black==19.10b0" "isort==4.3.21" "mypy==0.782"
 ```
 
 ### Code development
@@ -126,6 +126,14 @@ CI_PYTHON_VERSION=<your python version, e.g 3.7> sh tests/run_cpu_tests.sh
 # CI_PYTHON_VERSION=3.7 sh tests/run_cpu_tests.sh
 ```
 
+#### Run Mypy checks:
+To run mypy to check the optional static type:
+```bash
+mypy --config-file mypy.ini
+```
+
+To change any config for specif folder, please see the file mypy.ini
+
 #### Send a PR
 
 If everything is OK, please send a Pull Request to https://github.com/pytorch/ignite

mypy.ini

@@ -0,0 +1,32 @@
+[mypy]
+files = ignite
+pretty = True
+show_error_codes = True
+
+[mypy-ignite.base.*]
+
+ignore_errors = True
+
+[mypy-ignite.contrib.*]
+
+ignore_errors = True
+
+[mypy-ignite.handlers.*]
+
+ignore_errors = True
+
+[mypy-ignite.engine.*]
+
+ignore_errors = True
+
+[mypy-ignite.metrics.*]
+
+ignore_errors = True
+
+[mypy-ignite.distributed.*]
+
+ignore_errors = True
+
+[mypy-ignite.utils.*]
+
+ignore_errors = True