python code to launch,list and terminate EC2 instances

start_stop_ec2.py

import boto3 # a development kit package in AWS 
import os    # package which runs shell commands
import time  # package which handles date and time
def get_ec2_con_for_give_region(my_region):   #  function definition to get region
                ec2_con_re=boto3.resource('ec2',region_name=my_region)
                return ec2_con_re
def list_instances_on_my_region(ec2_con_re):  # function definition to get instance in that respective region
   for each in ec2_con_re.instances.all():
       print(each.id)
def get_instant_state(ec2_con_re,in_id):    # function definition to get the state of instances in that respective region
    for each in ec2_con_re.instances.filter(Filters=[{'Name':'instance-id',"values":[in_id]}]):
             pr_st=each.state['Name']
    return pr_st

def start_instance(ec2_con_re,in_id):  # function for starting or launching an instance
         pr_st=get_instant_state(ec2_con_re,in_id)
    # if instances are already in a run state 
         if pr_st=="running":
                 print("instance is already running")
      
         else:
               for each in ec2_con_re.instances.filter(Filters=[{'Name':'instance-id',"values":[in_id]}]):
                        each.start()
                        print("please wait it is goiong to start,once if it is started then we will let you know")
                        each.wait_untilrunning()
                        print("noe it is running")
         return
def Thank_you():
        print("\n\n*******************Thank You******************")
        return none
def stop_instance(ec2_con_re,in_id): # Function which stops the instance, by getting the id of respective instance
        pr_st=get_instant_state(ec2_con_re,in_id)
    # if the mentioned instance have already terminated 
        if pr_st=="stopped":
                print("Instance is already stop")
        else:
               for each in ec2_con_re.instances.filter(Filters=[{'Name':'instance-id',"values":[in_id]}]):
                   each.stop()
                   print("please wait it is going to stop")
                   each.wait_until_stopped()
                   print("now it stopped")
def welcome():
        print("this helps in start and stop of ec2")
        time.sleep(3)
def main(): # main function for basic tasks(inputs and other such stuffs)
        welcome()
        my_region=input("enter your region name:")
        print("please wait")
        ec2_con_re=get_ec2_con_for_give_region(my_region)
        print("please wait listing instances in your region {}.format(my_region)")
        list_instances_on_my_region(ec2_con_re)
        in_id=input("noe choose instance id to start or stop")
        start_stop=input("enter either start or stop")
        while True:
                if start_stop not in ["start","stop"]:
                   start_stop = input("enter only start or stop")
                   continue
                else:
                      break
        if start_stop == "start":
                start_instance(ec2_con_re,in_id)
        else:
             stop_instance(ec2_con_re,in_id)
        Thank_you()


if__name__== '__main__':
       os.system('cls')
       main