[Python] How to simulate P2P nodes and a double-spending attack in a Flask-based blockchain?

I'm working on a simple blockchain simulation using Python and Flask, mainly to understand how double-spending attacks and fork resolution work. Each node is a separate Flask app instance running on a different port. Nodes communicate by sending HTTP requests to each other (e.g., /receive_transaction, /receive_block), which works fine for basic transaction propagation and mining. Now I want to simulate a scenario where one node acts maliciously by:

• Withholding blocks it mines (creating a private chain)
• Later broadcasting its longer chain to override the public one
• Causing a double-spend by including conflicting transactions

I have basic Proof-of-Work and transaction validation working, but

I’m not sure how to properly implement:

• The attack logic: How to delay the attacker’s broadcast?
• P2P simulation: How to make communication between nodes feel more realistic in Flask?
• Hash rate simulation: Any ideas on modeling a higher mining power for the attacker node?

Is Flask even the right tool to simulate P2P behavior in this case, or should I use sockets/async instead? Any pointers or suggestions would be appreciated.

I set up multiple Flask apps running on different ports to act as individual nodes. Each node can receive and forward transactions or blocks via HTTP requests. I expected this to mimic basic P2P behavior, and it works for broadcasting single transactions or mined blocks.

For the attack simulation, I created an "attacker" node that mines its own private chain and delays broadcasting. I expected that when it broadcasts the longer chain later, it would override the public chain on other nodes. But it doesn't always work as expected — sometimes nodes don’t accept the longer chain, or the synchronization between nodes becomes inconsistent.

I'm trying to find a more reliable or realistic way to simulate this fork and override behavior.

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