搜索 function 不适用于 hash 表

Question

I am working on a project using Flask where i need to store a Hash Table in a file so that i can keep track of the Hash Table whenever user adds,updates the data in the Hash Table and so that i can get the Hash Table back当服务器关闭时再次。

import pickle
# get the last saved(last updated version) hash_table from the file
with open('hashtable.data', 'rb') as filehandle:
    # read the data as binary data stream
    hash_table= pickle.load(filehandle)

当用户添加新数据时，我将其插入 hash 表并将更改存储到文件中。

insert(hash_table,id,{'song':name,'artist':artist,'date':date})
with open('hashtable.data', 'wb') as filehandle:
    # store the data as binary data stream
      pickle.dump(hash_table, filehandle)

问题是即使 hash_table 数组中有数据，搜索函数也总是返回 None 。

def search(hash_table, key):
    hash_key = hash(key) % len(hash_table)    
    bucket = hash_table[hash_key]
    for i, kv in enumerate(bucket):
        k, v = kv
        if key == k:
            return v

 id=request.form.get('id')
 ans=search(hash_table,id)
 return render_template('searchresults.html',v=ans)

这返回：无