Python实现IPFS哈希主列表的查重与新增功能求助

Hey Troy! Sounds like a solid project—let's put together a flexible Python script that manages your IPFS hash list with duplicate checks, and set it up so you can easily add features later.

First, Let's Define the JSON Structure #

Let's start with a simple, scalable JSON format. Your file (let's call it ipfs_hashes.json) will look like this:

[
  {
    "hash": "QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG",
    "description": "Sample IPFS hash for test content"
  }
]

This array of dictionaries makes it easy to search, add, and modify entries down the line.

Step 1: Core Functions to Handle the JSON File #

We'll write reusable functions to load existing data, check for duplicates, add new entries, and save changes—keeping everything modular for future expansion.

1. Load Existing Hash Data #

First, a function to load the JSON file. We'll handle the case where the file doesn't exist yet by automatically creating an empty list to start fresh:

import json
from typing import List, Dict

def load_ipfs_hashes(file_path: str) -> List[Dict]:
    try:
        with open(file_path, 'r') as f:
            return json.load(f)
    except FileNotFoundError:
        # Return empty list if file doesn't exist
        return []

2. Duplicate Check Function #

This function will quickly check if a given IPFS hash already exists in your list:

def is_hash_duplicate(hashes_list: List[Dict], new_hash: str) -> bool:
    # Use `any()` for efficiency—it stops checking as soon as a match is found
    return any(entry['hash'] == new_hash for entry in hashes_list)

3. Add New Hash Entry Safely #

Combine the above functions to add a new hash only if it's not a duplicate, then save the updated list back to JSON:

def add_ipfs_hash(file_path: str, new_hash: str, description: str) -> bool:
    hashes_list = load_ipfs_hashes(file_path)
    
    if is_hash_duplicate(hashes_list, new_hash):
        print(f"Error: Hash {new_hash} already exists in the list!")
        return False
    
    # Add the new entry to the list
    hashes_list.append({
        "hash": new_hash,
        "description": description
    })
    
    # Save the updated list back to JSON with indentation for readability
    with open(file_path, 'w') as f:
        json.dump(hashes_list, f, indent=2)
    
    print(f"Successfully added hash: {new_hash}")
    return True

Step 4: Test It Out! #

Use the functions like this to start adding entries:

# Example usage
if __name__ == "__main__":
    IPFS_FILE = "ipfs_hashes.json"
    # Add a new valid entry
    add_ipfs_hash(IPFS_FILE, "QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG", "Test content for IPFS")
    # Try adding the same hash again (should trigger duplicate error)
    add_ipfs_hash(IPFS_FILE, "QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG", "Duplicate test")

Ideas for Future Expansion #

Since you want to expand this later, here are some easy, modular next steps:

• Search Function: Add a function to look up entries by hash or description (e.g., search_hashes(hashes_list, keyword="backup"))
• Command-Line Interface: Use argparse to let you add/search hashes directly from the terminal, like python ipfs_tracker.py add QmXYZ... "My new project file"
• IPFS Integration: Use the ipfshttpclient library to automatically generate hashes from local files and add them to your list in one step
• Hash Validation: Add checks to ensure the input is a valid IPFS hash (e.g., starts with Qm for CIDv0 or bafybe for CIDv1)
• Backup System: Add a function to create timestamped backups of your JSON file before making changes

This setup keeps everything decoupled, so you can add new features without breaking existing functionality.

内容的提问来源于stack exchange，提问作者Troy Wilson