PyKnow 诊断引擎示例：基于症状进行疾病诊断

The code provided is a simple example of a diagnosis engine using the PyKnow library. It defines a knowledge engine class called "DiagnosisEngine" that contains rules for diagnosing different diseases based on the symptoms provided.\n\nIn this example, the engine is initialized and the user inputs the symptoms of cough and fever. The engine then runs and uses the rules to make a diagnosis. In this case, the output of the engine would be "Diagnosis: Influenza" as the symptoms match the rule for diagnosing the flu.\n\nIt is important to note that this is a simplified example and in a real-world scenario, there would be more complex rules and a larger knowledge base to make accurate diagnoses.