how can I execute a function by calling its value in a dictionary

Question

I have this code:

import random
import datetime

def greet():
  response = random.choice(['hello sir', 'hi sir', 'welcome sir'])
  print(response)


def time():
  time = datetime.datetime.now().strftime('%I:%M %p')
  response = random.choice(['current time is', 'the time is', 'time is'])
  print(response + time)

commands = {'greet me': greet, 'what is the time': time}

while True:
  command = input('Enter your message: ')
  if command in commands:

then I want it to execute the function according to the user input