Python Engine
ZEN Engine is built as embeddable BRE for your Rust, NodeJS, Go or Python applications.
Installation
pip install zen-engine
Usage
To execute a simple decision you can use the code below.
import zen
# Example filesystem content, it is up to you how you obtain content
with open("./jdm_graph.json", "r") as f:
content = f.read()
engine = zen.ZenEngine()
decision = engine.create_decision(content)
result = decision.evaluate({"input": 15})
Loaders
For more advanced use cases where you want to load multiple decisions and utilise graphs you can build loaders.
import zen
def loader(key):
with open("./jdm_directory/" + key, "r") as f:
return f.read()
engine = zen.ZenEngine({"loader": loader})
result = engine.evaluate("jdm_graph1.json", {"input": 5})
or
...
engine = zen.ZenEngine({"loader": loader})
decision = engine.get_decision("jdm_graph1.json")
result = decision.evaluate({"input": 5})
When engine.evaluate is invoked it will call loader and pass a key expecting a content of the JDM decision graph. In the case above we will assume file jdm_directory/jdm_graph1.json exists.
Similar to this example you can also utilise loader to load from different places, for example from REST API, from S3, Database, etc.
Evaluate expressions
You may also evaluate singular ZEN Expressions.
import zen
zen.evaluate_expression("1 + 1") # 2
zen.evaluate_expression("a + b", { "a": 10, "b": 20 }) # 30
zen.evaluate_unary_expression("> 10", { "$": 5 }) # false
zen.evaluate_unary_expression("> 10", { "$": 15 }) # true