Add python type annotations to api.py (#1061)

This will also check the types using mypy on the CI.

.github/workflows/ci.yaml

@@ -142,10 +142,12 @@ jobs:
       with:
         python-version: 3.6
     - name: Install pyflakes
-      run: pip install pyflakes==2.3.1
+      run: pip install pyflakes==2.3.1 mypy==0.931
 
     - name: Run pyflakes
-      run: pyflakes examples/ tools/ src/ test/ doc/
+      run: |
+        pyflakes examples/ tools/ src/ test/ doc/
+        mypy tools/api.py
 
   linux:
 

tools/generate.sh

 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 SRC_DIR=$DIR/../src
-ls -1 $DIR/include/ | xargs -n 1 -P $(nproc) -I{} -t bash -c "python3.6 $DIR/te.py $DIR/include/{} | clang-format-5.0 -style=file > $SRC_DIR/include/migraphx/{}"
+PYTHON=python3
+if type -p python3.6 > /dev/null ; then
+    PYTHON=python3.6
+fi
+if type -p python3.8 > /dev/null ; then
+    PYTHON=python3.8
+fi
+ls -1 $DIR/include/ | xargs -n 1 -P $(nproc) -I{} -t bash -c "$PYTHON $DIR/te.py $DIR/include/{} | clang-format-5.0 -style=file > $SRC_DIR/include/migraphx/{}"
 
 function api {
-    python3.6 $DIR/api.py $SRC_DIR/api/migraphx.py $1 | clang-format-5.0 -style=file > $2
+    $PYTHON $DIR/api.py $SRC_DIR/api/migraphx.py $1 | clang-format-5.0 -style=file > $2
 }
 
 api $DIR/api/migraphx.h $SRC_DIR/api/include/migraphx/migraphx.h