diff --git a/python_terraform/__init__.py b/python_terraform/__init__.py
index 86bcb7d..8de4c0b 100644
--- a/python_terraform/__init__.py
+++ b/python_terraform/__init__.py
@@ -16,6 +16,10 @@ class IsFlagged:
     pass
 
 
+class IsNotFlagged:
+    pass
+
+
 class Terraform(object):
     """
     Wrapper of terraform command line tool
@@ -64,20 +68,28 @@ class Terraform(object):
 
         return wrapper
 
-    def apply(self, dir_or_plan=None, **kwargs):
+    def apply(self, dir_or_plan=None, input=False, no_color=IsFlagged, **kwargs):
         """
         refer to https://terraform.io/docs/commands/apply.html
         no-color is flagged by default
+        :param no_color: disable color of stdout
+        :param input: disable prompt for a missing variable
         :param dir_or_plan: folder relative to working folder
         :param kwargs: same as kwags in method 'cmd'
         :returns return_code, stdout, stderr
         """
-        default = dict()
-        args, option_dict = self._generate_default_args(dir_or_plan, default, kwargs)
+        default = kwargs
+        default['input'] = input
+        default['no_color'] = no_color
+        option_dict = self._generate_default_options(default)
+        args = self._generate_default_args(dir_or_plan)
         return self.cmd('apply', *args, **option_dict)
 
-    def _generate_default_args(self, dir_or_plan, default_dict, kwargs):
-        option_dict = default_dict
+    def _generate_default_args(self, dir_or_plan):
+        return [dir_or_plan] if dir_or_plan else []
+
+    def _generate_default_options(self, input_options):
+        option_dict = dict()
         option_dict['state'] = self.state
         option_dict['target'] = self.targets
         option_dict['var'] = self.variables
@@ -85,18 +97,19 @@ class Terraform(object):
         option_dict['parallelism'] = self.parallelism
         option_dict['no_color'] = IsFlagged
         option_dict['input'] = False
-        option_dict.update(kwargs)
-        args = [dir_or_plan] if dir_or_plan else []
-        return args, option_dict
+        option_dict.update(input_options)
+        return option_dict
 
-    def destroy(self, dir_or_plan=None, **kwargs):
+    def destroy(self, dir_or_plan=None, force=IsFlagged, **kwargs):
         """
         refer to https://www.terraform.io/docs/commands/destroy.html
         force/no-color option is flagged by default
         :return: ret_code, stdout, stderr
         """
-        default = {'force': IsFlagged}
-        args, option_dict = self._generate_default_args(dir_or_plan, default, kwargs)
+        default = kwargs
+        default['force'] = force
+        option_dict = self._generate_default_options(default)
+        args = self._generate_default_args(dir_or_plan)
         return self.cmd('destroy', *args, **option_dict)
 
     def generate_cmd_string(self, cmd, *args, **kwargs):
@@ -148,7 +161,7 @@ class Terraform(object):
                 cmds += ['-{k}'.format(k=k)]
                 continue
 
-            if v is None:
+            if v is None or v is IsNotFlagged:
                 continue
 
             if type(v) is bool: