Lockdown cafe

• Read the guideline before starting.
• If you need additional information about datetime module you can find it here.

Implement a Cafe class, whose instances have one attribute name. Write a visit_cafe method with one parameter, visitor of type dict. Due to the pandemic, not everyone can visit the cafe.

If the visitor does not have a vaccine key, it means that he is not vaccinated. In this case, the method must raise a NotVaccinatedError exception.

kfc = Cafe("KFC")
visitor = {
    "name": "Paul",
    "age": 23,
}
kfc.visit_cafe(visitor)     # NotVaccinatedError

The vaccine must not be expired, otherwise the method should raise an OutdatedVaccineError exception. You can get an expiration_date from visitor["vaccine"] dictionary.

import datetime

kfc = Cafe("KFC")
visitor = {
    "name": "Paul",
    "age": 23,
    "vaccine": {
        "expiration_date": datetime.date(year=2019, month=2, day=23)
    }
}
kfc.visit_cafe(visitor)     # OutdatedVaccineError

And the last rule: all visitors must wear masks. Otherwise visit_cafe should raise an NotWearingMaskError exception.

kfc = Cafe("KFC")
visitor = {
    "name": "Paul",
    "age": 23,
    "vaccine": {
        "expiration_date": datetime.date.today()
    },
    "wearing_a_mask": False
}
kfc.visit_cafe(visitor)     # NotWearingMaskError

If all the rules are met, then the person can visit the cafe and the method should return the string "Welcome to {cafe.name}"

kfc = Cafe("KFC")
visitor = {
    "name": "Paul",
    "age": 23,
    "vaccine": {
        "expiration_date": datetime.date.today()
    },
    "wearing_a_mask": True
}
kfc.visit_cafe(visitor) == "Welcome to KFC"

Write a function go_to_cafe which takes a friends list and a cafe. It should return a string "Friends can go to {cafe.name}" if they are all allowed to visit it.

If at least one of the friend has problems with vaccines the function should return a message `"All friends should be vaccinated".

If everyone is vaccinated but somebody isn't wearing a mask the function should return a message "Friends should buy {masks_to_buy} masks" where masks_to_buy is the number of friends who don't have a mask.

friends = [
    {
        "name": "Alisa",
        "vaccine": {
            "expiration_date": datetime.date.today()
        },
        "wearing_a_mask": True
    },
    {
        "name": "Bob",
        "vaccine": {
            "expiration_date": datetime.date.today()
        },
        "wearing_a_mask": True
    },
]
go_to_cafe(friends, Cafe("KFC")) == "Friends can go to KFC"

friends = [
    {
        "name": "Alisa",
        "vaccine": {
            "expiration_date": datetime.date.today()
        },
        "wearing_a_mask": False
    },
    {
        "name": "Bob",
        "vaccine": {
            "expiration_date": datetime.date.today()
        },
        "wearing_a_mask": False
    },
]
go_to_cafe(friends, Cafe("KFC")) == "Friends should buy 2 masks"

friends = [
    {
        "name": "Alisa",
        "wearing_a_mask": True
    },
    {
        "name": "Bob",
        "vaccine": {
            "expiration_date": datetime.date.today()
        },
        "wearing_a_mask": True
    },
]
go_to_cafe(friends, Cafe("KFC")) == "All friends should be vaccinated"

Use the following project structure:

    main.py
    cafe.py
    errors.py

All errors should be defined in the errors.py module. The Cafe class should be defined in cafe.py module. The function should be implemented in main.py module.

Notes:

• Use try/except to handle errors in go_to_cafe
• Be sure to pass descriptive messages when you raise the exception in the visit_cafe method
• Create a VaccineError parent class for NotVaccinatedError and OutdatedVaccineError errors. Use it to catch both types of errors in the same except clause.
• You can work with dates using datetime module.
• You can compare two dates using < operator:

import datetime
date1 = datetime.date(2020, 3, 4)
date2 = datetime.date(2022, 1, 30)

assert  date1 < date2

• To get the current date use datetime.date.today()

Note: Check your code using this checklist before pushing your solution.