pip-services3-commons 3.3.3

Basic portable abstractions for Pip.Services in Python

Portable Abstractions and Patterns for Python

This module is a part of the Pip.Services polyglot microservices toolkit. It provides a set of basic patterns used in microservices or backend services. Also the module implemenets a reasonably thin abstraction layer over most fundamental functions across all languages supported by the toolkit to facilitate symmetric implementation.

The module contains the following packages:

• Commands - commanding and eventing patterns
• Config - configuration pattern
• Convert - portable value converters
• Data - data patterns
• Errors- application errors
• Random - random data generators
• Refer - locator inversion of control (IoC) pattern
• Reflect - portable reflection utilities
• Run - component life-cycle management patterns
• Validate - validation patterns

Quick links:

• Configuration Pattern
• Locator Pattern
• Component Lifecycle
• Components with Active Logic
• Data Patterns
• API Reference
• Change Log
• Get Help
• Contribute

Use

Install the Python package as

pip install pip_services3_commons

Then you are ready to start using the Pip.Services patterns to augment your backend code.

For instance, here is how you can implement a component, that receives configuration, get assigned references, can be opened and closed using the patterns from this module.

from pip_services3_commons.config import IConfigurable, ConfigParams
from pip_services3_commons.refer import IReferenceable, IReferences, Descriptor
from pip_services3_commons.run import IOpenable


class MyComponentA(IConfigurable, IReferenceable, IOpenable):
    _param1 = 'ABC'
    _param2 = 123
    _another_component: MyComponentB
    _opened = True

    def configure(self, config):
        self._param1 = ConfigParams.get_as_string_with_default("param1", self._param1)
        self._param2 = config.get_as_integer_with_default("param2", self._param2)

    def set_references(self, references):
        self._another_component = references.get_one_required(
            Descriptor("myservice", "mycomponent-b", "*", "*", "1.0")
        )

    def is_opened(self):
        return self._opened

    def open(self, correlation_id):
        self._opened = True
        print("MyComponentA has been opened.")

    def close(self, correlation_id):
        self._opened = True
        print("MyComponentA has been closed.")

Then here is how the component can be used in the code

from pip_services3_commons.config import IConfigurable, ConfigParams
from pip_services3_commons.refer import References, Descriptor

my_component_A = MyComponentA()

# Configure the component
my_component_A.configure(ConfigParams.from_tuples(
    'param1', 'XYZ',
    'param2', 987
))

# Set references to the component
my_component_A.set_references(References.from_tuples(
    Descriptor("myservice", "mycomponent-b", "default", "default", "1.0"), my_component_B
))

# Open the component
my_component_A.open("123")
print("MyComponentA has been opened.")

Develop

For development you shall install the following prerequisites:

• Python 3.7+
• Visual Studio Code or another IDE of your choice
• Docker

Install dependencies:

pip install -r requirements.txt

Run automated tests:

python test.py

Generate API documentation:

./docgen.ps1

Before committing changes run dockerized build and test as:

./build.ps1
./test.ps1
./clear.ps1

Contacts

The library is created and maintained by:

• Sergey Seroukhov
• Danil Prisiazhnyi