public/subjects/devops/days_and_numbers

Days and numbers

Instructions

Create a file custom_calendar.py which will have 2 functions:

• day_from_number(day_number)
• day_to_number(day)

Those functions perform conversion between day index and day word:

• 1 = Monday
• 2 = Tuesday
• 3 = Wednesday
• 4 = Thursday
• 5 = Friday
• 6 = Saturday
• 7 = Sunday

You should return None if the input is invalid (invalid number or day string).

Usage

Here is a possible test.py to test your functions:

import custom_calendar

print(custom_calendar.day_from_number(2))
print(custom_calendar.day_from_number(1))
print(custom_calendar.day_from_number(1000))
print(custom_calendar.day_to_number('Sunday'))
print(custom_calendar.day_to_number('invalid day'))

$ python test.py
Tuesday
Monday
None
7
None
$

Hints

Dictionaries:

A dictionary is a data type similar to arrays, but works with keys and values instead of indexes. Each value stored in a dictionary can be accessed using a key, which is any type of object (a string, a number, a list, etc.) instead of using its index to address it.

For example, a database of phone numbers could be stored using a dictionary like this:

phonebook = {}
phonebook["John"] = 938477566
phonebook["Jack"] = 938377264
phonebook["Jill"] = 947662781
print(phonebook)

output:

{'John': 938477566, 'Jack': 938377264, 'Jill': 947662781}

Alternatively, a dictionary can be initialized with the same values in the following notation:

phonebook = {
    "John" : 938477566,
    "Jack" : 938377264,
    "Jill" : 947662781
}
print(phonebook)

Dictionaries can be iterated over, just like a list. To iterate over key value pairs, use the following syntax:

phonebook = {"John": 938477566, "Jack": 938377264, "Jill": 947662781}
for name, number in phonebook.items():
    print("Phone number of %s is %d" % (name, number))

output:

Phone number of John is 938477566
Phone number of Jack is 938377264
Phone number of Jill is 947662781

References

• None type
• Dictionaries
• Access an item in dictionary