fix putenv()

Author: glaukiol1

os/os.module.go

@@ -117,19 +117,19 @@ func getpid(self py.Object, args py.Tuple) (py.Object, error) {
 // putenv sets the value of an environment variable named by the key.
 func putenv(self py.Object, args py.Tuple) (py.Object, error) {
 	if len(args) != 2 {
-		//... return error ...
+		return nil, py.ExceptionNewf(py.TypeError, "missing required arguments: 'key:str' and 'value:str'")
 	}
 	k, ok := args[0].(py.String)
 	if !ok {
-		//... return error ...
+		return nil, py.ExceptionNewf(py.TypeError, "str expected (pos 1), not "+args[0].Type().Name)
 	}
 	v, ok := args[1].(py.String)
 	if !ok {
-		//... return error ...
+		return nil, py.ExceptionNewf(py.TypeError, "str expected (pos 2), not "+args[1].Type().Name)
 	}
 	err := os.Setenv(string(k), string(v))
 	if err != nil {
-		return ...
+		return nil, py.ExceptionNewf(py.OSError, "Unable to set enviroment variable")
 	}
 	return py.None, nil
 }