diff --git a/README.md b/README.md
index 1735927..6efd1e2 100644
--- a/README.md
+++ b/README.md
@@ -13,21 +13,21 @@ python-terraform is a python module provide a wrapper of `terraform` command lin
 For any terraform command
 
     def cmd(self, cmd, *args, **kwargs):
-    """
-    run a terraform command, if success, will try to read state file
-    :param cmd: command and sub-command of terraform, seperated with space
-                refer to https://www.terraform.io/docs/commands/index.html
-    :param args: arguments of a command
-    :param kwargs:  any option flag with key value without prefixed dash character
-            if there's a dash in the option name, use under line instead of dash,
-                ex. -no-color --> no_color
-            if it's a simple flag with no value, value should be IsFlagged
-                ex. cmd('taint', allow＿missing=IsFlagged)
-            if it's a boolean value flag, assign True or false
-            if it's a flag could be used multiple times, assign list to it's value
-            if it's a "var" variable flag, assign dictionary to it
-            if a value is None, will skip this option
-    :return: ret_code, out, err
+        """
+        run a terraform command, if success, will try to read state file
+        :param cmd: command and sub-command of terraform, seperated with space
+                    refer to https://www.terraform.io/docs/commands/index.html
+        :param args: arguments of a command
+        :param kwargs:  any option flag with key value without prefixed dash character
+                if there's a dash in the option name, use under line instead of dash,
+                    ex. -no-color --> no_color
+                if it's a simple flag with no value, value should be IsFlagged
+                    ex. cmd('taint', allow＿missing=IsFlagged)
+                if it's a boolean value flag, assign True or false
+                if it's a flag could be used multiple times, assign list to it's value
+                if it's a "var" variable flag, assign dictionary to it
+                if a value is None, will skip this option
+        :return: ret_code, out, err
 
 For apply/destroy method, the flag options, like, `-no-color` or `-force`
 have been implemented as boolean argument. simply use `is_no_color=True/False` for