thepocagency / pydictchecker

PyDictChecker is a generic Python3 tool to run recursively through a dictionary and validate any kind of conditions in a given dictionary.

PyDictChecker

Table of content

1. What is PyDictChecker?
2. Examples
3. Default comparators / cast-operators
4. Main commands
   1. Test
   2. Build
   3. Import PyDictChecker into your project
5. Credits

What is PyDictChecker?

PyDictChecker is a generic Python3 tool to run recursively through a dictionary and validate any kind of conditions in a given dictionary.

It is designed as a ''dictionary parser'' to verify element existence & value.

You can use ''human-readable'' rule to move on a node and check recursively and relatively any conditions (and sub-conditions).

Examples

Let's say you have the dictionary below:

music_library = {
    'artists': [
        {
            'id': 1,
            'real_name': {
                'firstname': 'Jean - Philippe Léo',
                'lastname': 'Smet'
            },
            'artist_name' : {
                'firstname': 'Johnny',
                'lastname': 'Hallyday',
            },
            'albums': [
                {
                    'year': 1961,
                    'name': 'Salut les copains'
                },
                {
                    'year': 1961,
                    'name': 'Nous les gars, nous les filles'
                },
                {
                    'year': 1962,
                    'name': 'Sings Americas Rockin Hits'
                }
            ]
        }
    ]
}

Ex. 1

If you want to verify if the last artist has at least one album:

_is_valid, _output_value = PyDictChecker.check(music_library, [
    {
        'path': 'artists->:last:->albums->:first:'
    }
])

NB:

• ''_is_valid'' is valid in this case because the node exists
• ''_output_value'' is the first album in this case

Ex. 2

If you want to check if:

• the first artist exists;
• and his real lastname is 'Smet';
• and his third album was published after 1961.

You can run the next method:

_is_valid, _output_value = PyDictChecker.check(music_library, [
    {
        'path': 'artists->:first:',
        'conditions': [
            {
                'path': 'real_name->lastname',
                'comparator': '==',
                'comparative_value': 'Smet',
                'cast_to': None,
                'output': True
            },
            {
                'path': 'albums->:pos:2->year',
                'comparator': '>',
                'comparative_value': 1960,
                'cast_to': ':int:'
            }
        ]
    }
])

NB:

• please note that we use relative path in this case.
• the boolean ''_is_valid'' is valid and we get the value 'Smet' in ''_output_value''

More

See / run this test file py_dict_checker_test.py for more details.

Default comparators / cast-operators

So far, there are only these next comparators: '>', '<', '>=', '<=', '==', '!='.

And these are the first operators:

• to cast a string to an integer, with :int:
• to move into a dict:
  • :first:,
  • :last:,
  • :pos:X (where X is the position of the element you want to move to)

Main commands

Test

 $ python -m unittest discover -v -s . -p "*_test.py"

Build

To create a build version in the "dist" directory

 $ python setup.py sdist

Import PyDictChecker into your project

This project is not listed on Pypi but you can import it from Github:

 $ . venv/bin/activate
 $ pip install -e git+https://github.com/thepocagency/pydictchecker.git#egg=pydictchecker
 $ pip freeze > requirements.txt

Credits

Developed by Alexandre Veremme @ The POC Agency (cf. www.the-poc-agency.com)