resovle go-python#169 (comment)

Author: glaukiol1

os/os.module.go

@@ -92,40 +92,21 @@ func chdir(self py.Object, args py.Tuple) (py.Object, error) {
 // getenv returns the value of the environment variable key.
 // If no such environment variable exists and a default value was provided, that value is returned.
 func getenv(self py.Object, args py.Tuple) (py.Object, error) {
-	var (
-		key  py.Object
-		dflt py.Object = py.None
-		err  error
-	)
-	if len(args) == 0 {
+	if len(args) < 1 {
 		return nil, py.ExceptionNewf(py.TypeError, "missing one required argument: 'name:str'")
 	}
-	if !objectIsString(args[0]) {
+	k, ok := args[0].(py.String)
+	if !ok {
 		return nil, py.ExceptionNewf(py.TypeError, "str expected (pos 1), not "+args[0].Type().Name)
 	}
-	switch len(args) {
-	case 1:
-		key = args[0]
-		dflt = py.None
-	case 2:
-		key = args[0]
-		if !objectIsString(args[1]) {
-			return nil, py.ExceptionNewf(py.TypeError, "str expected (pos 2), not "+args[1].Type().Name)
-		}
-		dflt = args[1]
-	}
-	gokey, err := py.ReprAsString(key)
-	if err != nil {
-		return dflt, nil
+	v, ok := os.LookupEnv(string(k))
+	if ok {
+		return py.String(v), nil
 	}
-	gokey = strings.ReplaceAll(gokey, "'", "")
-	for _, evar := range os.Environ() {
-		key_value := strings.SplitN(evar, "=", 2) // returns a []string containing [key,value]
-		if key_value[0] == gokey {
-			return py.String(key_value[1]), nil
-		}
+	if len(args) == 2 {
+		return args[1], nil
 	}
-	return dflt, nil
+	return py.None, nil
 }
 
 // get the current process' pid