resolve go-python#169 (comment)

Author: glaukiol1

main

@@ -68,7 +68,7 @@ func chdir(self py.Object, args py.Tuple) (py.Object, error) {
 	if len(args) == 0 || len(args) > 1 {
 		return nil, py.ExceptionNewf(py.TypeError, "One argument required")
 	}
-	if reflect.TypeOf(args[0]).String() == "py.String" {
+	if objectIsString(args[0]) {
 		dir, err := py.ReprAsString(args[0])
 		if err != nil {
 			return nil, py.ExceptionNewf(py.TypeError, "Failed to parse string")
@@ -94,14 +94,14 @@ func getenv(self py.Object, args py.Tuple) (py.Object, error) {
 		return nil, py.ExceptionNewf(py.KeyError, "1 argument required, \"key\"")
 	}
 	if len(args) == 1 {
-		if reflect.TypeOf(args[0]).String() == "py.String" {
+		if objectIsString(args[0]) {
 			key = args[0]
 		} else {
 			return nil, py.ExceptionNewf(py.TypeError, "Expected argument of type string")
 		}
 		default_ = py.None
 	} else if len(args) == 2 {
-		if reflect.TypeOf(args[0]).String() == "py.String" && reflect.TypeOf(args[1]).String() == "py.String" {
+		if objectIsString(args[1]) {
 			key = args[0]
 			default_ = args[1]
 		} else {
@@ -123,32 +123,30 @@ func getpid(self py.Object, args py.Tuple) (py.Object, error) {
 
 // Set the environment variable named key to the string value.
 func putenv(self py.Object, args py.Tuple) (py.Object, error) {
-	if len(args) == 2 {
-		if reflect.TypeOf(args[0]).String() == "py.String" && reflect.TypeOf(args[1]).String() == "py.String" {
-			_k, err := py.ReprAsString(args[0])
-			if err != nil {
-				return nil, py.ExceptionNewf(py.TypeError, "Unable to parse string") // this will never execute
-			}
-			key := strings.ReplaceAll(_k, "'", "") // required
-			_v, err := py.ReprAsString(args[1])
-			if err != nil {
-				return nil, py.ExceptionNewf(py.TypeError, "Unable to parse string") // this will never execute
-			}
-			value := strings.ReplaceAll(_v, "'", "")
+	if len(args) == 2 && objectIsString(args[0]) && objectIsString(args[1]) {
+		_k, err := py.ReprAsString(args[0])
+		if err != nil {
+			return nil, py.ExceptionNewf(py.TypeError, "Unable to parse string") // this will never execute
+		}
+		key := strings.ReplaceAll(_k, "'", "") // required
+		_v, err := py.ReprAsString(args[1])
+		if err != nil {
+			return nil, py.ExceptionNewf(py.TypeError, "Unable to parse string") // this will never execute
+		}
+		value := strings.ReplaceAll(_v, "'", "")
 
-			err = os.Setenv(key, value)
-			if err != nil {
-				return nil, py.ExceptionNewf(py.OSError, "Unable to set enviroment variable")
-			}
-			return py.None, nil
+		err = os.Setenv(key, value)
+		if err != nil {
+			return nil, py.ExceptionNewf(py.OSError, "Unable to set enviroment variable")
 		}
+		return py.None, nil
 	}
 	return nil, py.ExceptionNewf(py.TypeError, "Expected 2 arguments of type string")
 }
 
 // Unset (delete) the environment variable named key.
 func unsetenv(self py.Object, args py.Tuple) (py.Object, error) {
-	if len(args) == 1 {
+	if len(args) == 1 && objectIsString(args[0]) {
 		if reflect.TypeOf(args[0]).String() == "py.String" {
 			_k, err := py.ReprAsString(args[0])
 			if err != nil {
@@ -165,11 +163,12 @@ func unsetenv(self py.Object, args py.Tuple) (py.Object, error) {
 	return nil, py.ExceptionNewf(py.TypeError, "Expected 1 argument of type string")
 }
 
-// os._exit() immediate program termination; unline sys.exit(), which raises a SystemExit, this function will termninate the program immediately.
+// os._exit() immediate program termination; unlike sys.exit(), which raises a SystemExit, this function will termninate the program immediately.
 func _exit(self py.Object, args py.Tuple) (py.Object, error) { // can never return
 	if len(args) == 0 {
 		os.Exit(0)
-	} else if len(args) == 1 {
+	}
+	if len(args) == 1 && objectIsInt(args[0]) {
 		_ec, err := py.GetInt(args[0])
 		if err != nil {
 			os.Exit(1)
@@ -186,21 +185,17 @@ func _exit(self py.Object, args py.Tuple) (py.Object, error) { // can never retu
 
 // os.system(command string) this function runs a shell command and directs the output to standard output.
 func system(self py.Object, args py.Tuple) (py.Object, error) {
-	if len(args) == 0 {
+	if len(args) == 0 && !(objectIsString(args[0])) {
 		return nil, py.ExceptionNewf(py.TypeError, "Expected 1 or more arguments all of type string")
 	}
 	var cargs []string
-	if reflect.TypeOf(args[0]).String() == "py.String" {
-		_carg, err := py.ReprAsString(args[0])
-		if err != nil {
-			return nil, py.ExceptionNewf(py.TypeError, "Unable to parse string") // this will never execute
-		}
-		carg := strings.ReplaceAll(_carg, "'", "") // required
-
-		cargs = strings.Split(carg, " ")
-	} else {
-		return nil, py.ExceptionNewf(py.TypeError, "Expected 1 or more arguments all of type string")
+	_carg, err := py.ReprAsString(args[0])
+	if err != nil {
+		return nil, py.ExceptionNewf(py.TypeError, "Unable to parse string") // this will never execute
 	}
+	carg := strings.ReplaceAll(_carg, "'", "") // required
+
+	cargs = strings.Split(carg, " ")
 	command := exec.Command(cargs[0], cargs[1:]...)
 	outb, err := command.Output()
 	if err != nil {
@@ -209,3 +204,18 @@ func system(self py.Object, args py.Tuple) (py.Object, error) {
 	fmt.Println(string(outb)) // FIXME - use gpython Stdout
 	return py.Int(0), nil
 }
+
+// https://github.com/go-python/gpython/pull/169#discussion_r828767552 - type assertion
+func objectIsString(arg py.Object) bool {
+	if _, ok := arg.(py.String); ok {
+		return true
+	}
+	return false
+}
+
+func objectIsInt(arg py.Object) bool {
+	if _, ok := arg.(py.Int); ok {
+		return true
+	}
+	return false
+}