Zeller's Congruence Algorithm

[mrvnmchm]

Let me know of any other improvements I can make. 👍

Marvins-MBP:maths marvinmichum$ python3 zellers_congruence.py --help
usage: zellers_congruence.py [-h] date_input

Find out what day of the week nearly any date is or was. Enter date as a
string in the mm-dd-yyyy or mm/dd/yyyy format

positional arguments:
  date_input  Date as a string (mm-dd-yyyy or mm/dd/yyyy)

optional arguments:
  -h, --help  show this help message and exit

>>> import ZellersCongruence as z
>>> z.zeller('10/10/2018')
Your date 10/10/2018, is a Wednesday!
>>> z.zeller('04-23-1991')
Your date 04-23-1991, is a Tuesday!
>>> z.zeller('01-31-1976')
Your date 01-31-1976, is a Saturday!

Marvins-MBP:maths marvinmichum$ python3 zellers_congruence.py -v
Trying:
    zeller('01-31-2010')
Expecting:
    Your date 01-31-2010, is a Sunday!
ok
Trying:
    zeller('13-31-2010')
Expecting:
    Traceback (most recent call last):
    ...
    ValueError: Month must be between 1 - 12
ok
Trying:
    zeller('.2-31-2010')
Expecting:
    Traceback (most recent call last):
    ...
    ValueError: invalid literal for int() with base 10: '.2'
ok
Trying:
    zeller('01-33-2010')
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: Date must be between 1 - 31
ok
Trying:
    zeller('01-.4-2010')
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: invalid literal for int() with base 10: '.4'
ok
Trying:
    zeller('01-31*2010')
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: Date seperator must be '-' or '/'
ok
Trying:
    zeller('01^31-2010')
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: Date seperator must be '-' or '/'
ok
Trying:
    zeller('01-31-8999')
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: Year out of range. There has to be some sort of limit...right?
ok
Trying:
    zeller()
Expecting:
    Traceback (most recent call last):
        ...
    TypeError: zeller() missing 1 required positional argument: 'date_input'
ok
Trying:
    zeller('')
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: Must be 10 characters long
ok
Trying:
    zeller('01-31-19082939')
Expecting:
    Traceback (most recent call last):
        ...
    ValueError: Must be 10 characters long
ok
1 items had no tests:
    __main__
1 items passed all tests:
  11 tests in __main__.zeller
11 tests in 2 items.
11 passed and 0 failed.
Test passed.

[cclauss]

math imported but not used

[mrvnmchm]

Removed unused import.

[cclauss]

This is a great piece of work. I approve it in its current state.
Please consider adding one or more tests to compare zeller()'s results against the Python standard library results:

>>> from datetime import datetime
>>> f"{datetime(2019, 8, 4):%A}"

Just FYI: Dates are a pain in all programming languages but these two libraries help...
https://arrow.readthedocs.io
https://www.kennethreitz.org/essays/introducing-maya-datetimes-for-humans

[mrvnmchm]

Updated to add suggestions, and to fix the issue with TravisCI and the Dict annotation.