How to Resolve Circular Dependency in Python?

Circular Dependency in Python

Encountering a circular dependency can be a frustrating problem when working with Python modules. In this specific scenario, we have two files, node.py and path.py, containing the Node and Path classes, respectively.

Initially, path.py imported node.py using from node.py import *. However, after adding a new method to Node that references the Path object, importing path.py resulted in an error because Node was not defined.

To resolve the circular dependency, consider implementing the following:

Utilize lazy evaluation: Instead of importing one module inside another during initialization, import it only when necessary within a specific function. For instance, in node.py, only import Path when needed:

# in node.py 
from path import Path
class Node 
    ...

In path.py, import Node only within the method that requires it:

# in path.py
class Path
  def method_needs_node(): 
    from node import Node
    n = Node()
    ...

The above is the detailed content of How to Resolve Circular Dependency in Python?. For more information, please follow other related articles on the PHP Chinese website!