play-python

=========== play python

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pytest-play plugin with restricted Python expressions and assertions and it is based on the RestrictedPython package.

RestrictedPython is a tool that helps to define a subset of the Python language which allows to provide a program input into a trusted environment. RestrictedPython is not a sandbox system or a secured environment, but it helps to define a trusted environment and execute untrusted code inside of it.

See:

• https://github.com/zopefoundation/RestrictedPython

More info and examples on:

• pytest-play_, documentation
• cookiecutter-qa_, see pytest-play in action with a working example if you want to start hacking

Features

This project defines the following pytest-play_ commands based on Python expressions.

Store variables

You can store a pytest-play_ variables::

{
 'provider': 'python',
 'type': 'store_variable',
 'expression': '1+1',
 'name': 'foo'
}

Make a Python assertion

You can make an assertion based on a Python expression::

{
 'provider': 'python',
 'type': 'assert',
 'expression': 'variables["foo"] == 2'
}

Sleep

Sleep for a given amount of seconds::

{
 'provider': 'python',
 'type': 'sleep',
 'seconds': 2
}

Exec a Python expresssion

You can execute a Python expression::

{
 'provider': 'python',
 'type': 'exec',
 'expression': 'variables.update({'play_requests': {'parameters': {'headers': {'Authorization': '$bearer', 'Content-Type': 'application/json'}}}})'
}

Wait until condition

The wait_until_not command waits until the wait expression is False::

{
 'provider': 'python',
 'type': 'wait_until_not',
 'expression': 'variables["expected_id"] is not None and variables["expected_id"][0] == $id',
 'timeout': 5,
 'poll': 0.1,
 'subcommands': [{
     'provider': 'play_sql',
     'type': 'sql',
     'database_url': 'postgresql://$db_user:$db_pwd@$db_host/$db_name',
     'query': 'SELECT id FROM table WHERE id=$id ORDER BY id DESC;',
     'variable': 'expected_id',
     'expression': 'results.first()'
 }]
}

assuming that the subcommand updates the execution results updating a pytest-play variable (eg: expected_id) where tipically the $id value comes from a previously executed command that causes an asynchrounous update on a relational database soon or later (eg: a play_requests_ command making a HTTP POST call or a MQTT message coming from a simulated IoT device with play_mqtt_).

The wait command will try (and retry) to execute the subcommand with a poll frequency poll (default: 0.1 seconds) until the provided timeout expressed in seconds expires or an exception occurs.

You can use the opposite command named wait_until that waits until the wait expression is not False.

Loop commands

You can repeat a group of subcommands using a variable as a counter. Assuming you have defined a countdown variable with 10 value, the wait until command will repeat the group of commands for 10 times::

play_json.execute_command({
    'provider': 'python',
    'type': 'wait_until',
    'expression': 'variables["countdown"] == 0',
    'timeout': 0,
    'poll': 0,
    'sub_commands': [{
        'provider': 'python',
        'type': 'store_variable',
        'name': 'countdown',
        'expression': 'variables["countdown"] - 1'
    }]
})

Twitter

pytest-play tweets happens here:

• @davidemoro_

Credits

This package was created with Cookiecutter_ and the cookiecutter-play-plugin_ (based on audreyr/cookiecutter-pypackage_ project template).

.. _Cookiecutter: https://github.com/audreyr/cookiecutter .. _audreyr/cookiecutter-pypackage: https://github.com/audreyr/cookiecutter-pypackage .. _cookiecutter-play-plugin: https://github.com/tierratelematics/cookiecutter-play-plugin .. _pytest-play: https://github.com/tierratelematics/pytest-play .. _cookiecutter-qa: https://github.com/tierratelematics/cookiecutter-qa .. _@davidemoro: https://twitter.com/davidemoro .. _play_requests: https://github.com/tierratelematics/play_requests .. _play_mqtt: https://github.com/tierratelematics/play_mqtt

======= CHANGES

0.1.1 (2018-01-17)

• add filter and map

0.1.0 (2018-01-16)

• add wait_until and wait_until_not commands

• add datetime based expressions

• add json dumps and loads based expressions

0.0.1 (2018-01-10)

• First release