deltatime calculation

[D_frucht]

@J.crater, im sorry you are right. as you can see in the error below, the user input regarding order date was:2018-01-01. the user obligated to the client to deliver in 2 weeks. i want the outcome to show 2018-01-15
please see below the error:

Error:
Please enter client name: dd
Please enter model name: dd
Please enter quantity: 2
Please enter order date YYYY-MM-DD: 2018-01-01
Please enter number of weeks fot delivery date: 2
Traceback (most recent call last):
  File "/Users/davidfrucht/PycharmProjects/dfsl_db/DFSL.py", line 35, in <module>
    dynamic_data_entry()
  File "/Users/davidfrucht/PycharmProjects/dfsl_db/DFSL.py", line 19, in dynamic_data_entry
    delivery_date_c = datetime.date(order_date) + datetime.timedelta(weeks=delivery_date) # str(datetime.timedelta(weeks=delivery_date))
TypeError: an integer is required (got type str)