added getenv()

Author: glaukiol1

main

@@ -17,6 +17,7 @@ func init() {
 	methods := []*py.Method{
 		py.MustNewMethod("getcwd", getCwd, 0, "Get the current working directory"),
 		py.MustNewMethod("chdir", chdir, 0, "Change the current working directory"),
+		py.MustNewMethod("getenv", getenv, 0, "Return the value of the environment variable key if it exists, or default if it doesn’t. key, default and the result are str."),
 	}
 
 	globals := py.StringDict{
@@ -76,3 +77,37 @@ func chdir(self py.Object, args py.Tuple) (py.Object, error) {
 		}
 	}
 }
+
+// get a enviroment variable by key
+// Return the value of the environment variable key if it exists, or default if it doesn’t. key, default and the result are str.
+func getenv(self py.Object, args py.Tuple) (py.Object, error) {
+	var key py.Object      // key to search for
+	var default_ py.Object // return when not found
+	var err error          // error obj
+
+	if len(args) > 2 {
+		return nil, py.ExceptionNewf(py.KeyError, "1 argument required, \"key\"")
+	} else {
+		if len(args) == 1 {
+			if reflect.TypeOf(args[0]).String() == "py.String" {
+				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" {
+				key = args[0]
+				default_ = args[1]
+			} else {
+				return nil, py.ExceptionNewf(py.TypeError, "Expected argument of type string")
+			}
+		}
+		var res py.Object // hold the result value
+		res, err = getEnvVariables().M__getitem__(key)
+		if err != nil {
+			return default_, nil
+		}
+		return res, nil
+	}
+}

os/os.module.go

@@ -1,7 +1,13 @@
 import os
 
-print("OS Error ", os.error)
-print("$HOME", os.environ.get("HOME")) # prints $HOME variable
+print("os.error: ", os.error)
+print()
+print("$HOME: ", os.environ.get("HOME")) # prints $HOME variable
+print()
 print("cwd():", os.getcwd())
+print()
 print("chdir():", os.chdir(os.environ.get("HOME")))
+print()
 print("cwd() after chdir():", os.getcwd())
+print()
+print("getenv(\"HOME\"):", os.getenv("HOME"))