how to use flag in actions

[Vikas Kumar]

I am looking to use the flag such that

doit tf_init  runs terraform init command

and 

doit tf_init --upgrade runs terraform init -upgrade command

This is my pseudo code

def task_tf_init():

   def _task(flag):

      if flag:

          return '-upgrade'

       else:

           return ''

return {

'params': [{

'name': 'flag',

'long': 'upgrade',

'short': 'u',

'type': bool,

'default': False,

'inverse': 'upgrade'}],

'actions': [f'terraform init {(_task, )}',],

'verbosity': 2,

}