Exercise: Split Strings To User Dictionaries#

Plan#

User records are defined as lines of a file, where each line has the format

666:Jörg:Faschingbauer:1966-06-19

Our project, among other functionality, will provide a parsing routine that can read such lines, and create python user records as dictionaries of the form

{
    'id': 666,      # <-- int
    'firstname': 'Jörg',
    'lastname': 'Faschingbauer',
    'birth': '1966-06-19',
}

How#

In a project directory of your choice, create an empty file userdb.py. This file is a module which is supposed to contain project related functionality. Several programs will use that module’s contents, later in this exercise series.

At this stage in the project, lets only make sure that userdb works as intended, before combining the provided items (functions and classes) into programs that we can sell for money. We do this by writing unit tests.

Download the file below into the same directory that contains userdb.py.

code/test_read_userdicts_from_colon_separated_values.py#
import userdb

def test_read_users_from_colon_separated_values():
    input = [                                          # <-- file-like (iterable)
        '666:Jörg:Faschingbauer:1966-06-19\n',
        '42:Caro:Faschingbauer:1997-04-25\n',
        '7:Johanna:Faschingbauer:1995-06-11\n',
        '1024:Philipp:Lichtenberger:1986-04-06\n',
    ]

    users = userdb.read_users_from_colon_separated_values(input)

    assert len(users) == 4

    assert users[0]['id'] == 666
    assert users[0]['firstname'] == 'Jörg'
    assert users[0]['lastname'] == 'Faschingbauer'
    assert users[0]['birth'] == '1966-06-19'

    assert users[1]['id'] == 42
    assert users[1]['firstname'] == 'Caro'
    assert users[1]['lastname'] == 'Faschingbauer'
    assert users[1]['birth'] == '1997-04-25'

    assert users[2]['id'] == 7
    assert users[2]['firstname'] == 'Johanna'
    assert users[2]['lastname'] == 'Faschingbauer'
    assert users[2]['birth'] == '1995-06-11'

    assert users[3]['id'] == 1024
    assert users[3]['firstname'] == 'Philipp'
    assert users[3]['lastname'] == 'Lichtenberger'
    assert users[3]['birth'] == '1986-04-06'

Run the test (see below). It will complain that the functionality it is testing does not even exist, let alone does it fulfill any further requirements.

It is your task now to implement the required function (read_users_from_colon_separated_values()) in userdb.py, until everthing is green.

Do not modify the test, unless you discover severe errors - in this case, talk to your trainer and we will bend the requirements together.

$ python -m pytest
========================================================================== test session starts ==========================================================================
platform linux -- Python 3.13.7, pytest-8.4.2, pluggy-1.6.0
rootdir: /home/jfasch/My-Projects/jfasch-home/trainings/material/soup/python/exercises/userdb-2/code
collected 1 item

test_read_userdicts_from_colon_separated_values.py F                                                                                                                  [100%]

=============================================================================== FAILURES ================================================================================
______________________________________________________________ test_read_userdicts_from_colon_separated_values __________________________________________________________

    def test_read_userdicts_from_colon_separated_values():
        input = [                                          # <-- file-like (iterable)
            '666:Jörg:Faschingbauer:1966-06-19\n',
            '42:Caro:Faschingbauer:1997-04-25\n',
            '7:Johanna:Faschingbauer:1995-06-11\n',
            '1024:Philipp:Lichtenberger:1986-04-06\n',
        ]

>       persons = userdb.read_userdicts_from_colon_separated_values(input)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E       AttributeError: module 'userdb' has no attribute 'read_userdicts_from_colon_separated_values'

test_read_userdicts_from_colon_separated_values.py:11: AttributeError
======================================================================== short test summary info ========================================================================
FAILED test_read_userdicts_from_colon_separated_values.py::test_read_userdicts_from_colon_separated_values - AttributeError: module 'userdb' has no attribute 'read_userdicts_from_colon_separated_values'
=========================================================================== 1 failed in 0.03s ===========================================================================
(jfasch-home) jfasch@laptop:~/My-Projects/jfasch-home/trainings/material/soup/python/exercises/userdb-2/code$
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