To install the library:

pip install ppline

1. About

The library ppline can execute any class or any sequance of classes in any order. In other words, it is able to execute both:

• a specific class from a particular python file that can contain multiple classes, or
• an ordered sequence of specified classes from different python files.

2. How it works

2.1. Triggering a sequence of classes in order

To build a pipeline with classes to execute, you have to create a config .yml file in a root directory in the following form:

steps:
    [step name]:
        exec: [relative path to a file]:[class to execute]
    [step name]:
        exec: [relative path to a file]:[class to execute]
    [step name]:
        exec: [relative path to a file]:[class to execute]

Let's create a config .yml file with the name collect.yml:

steps:
    preProcessing:
        exec: src/calculation.py:Calculate
    kMeans:
        exec: src/models.py:Kmeans
    hyperTuning:
        exec: src/tuning.py:GridSearch

The executable classes specified in collect.yml should have a __call__ method. For instance, if we open aforementioned in collect.yml file in src/calculation.py and look at Calculate class that we trigger, we see call method in the end.

#this is src/calculation.py

class Calculate(object):
	def sum(self):
		a=2
		b=4
		self.c=a+b

	def divide(self):
		f=4
		self.d = self.c/f

    def show_result(self):
            print(self.d)

	def __call__(self):
		self.sum()
		self.divide()
        self.show_result()

In order for the ppline to work, you have to make sure that

• your code is module-enabled (you have to have __init__.py in every directory with .py files that you desire to execute classes from;
• the names of your steps in .yml are unique;

After creating a configuration .yml file in your root directory, use the following command to trigger the pipeline in terminal:

python -m ppline.cli --config_file collect.yml

2.2. Triggering one class from .py file

Ppline can also trigger a specific class from a specific .py file.

python -m ppline.cli --trigger_class path/to/file.py:TestClass

Below is an example of command that triggers a Calculate class from calculation.py file.

python -m ppline.cli --trigger_class src/calculation.py:Calculate

Note: Calculate class should have a __call__ method that executes desired class functions, and src/calculation.py should contain __init__.py file.

To do

• dependency map between steps
• independent steps in parallel
• make png export of visualized pipeline w/ names

Changes

0.2.5 (2021-08-08)

• feature to trigger a single class
• feature to generate gitlab-ci.yml file from the pipeline config file
• minor bug fixes

0.2.2 (2021-03-15)

• __call__ method is implemented
• minor bug fixes