如何将腌制的数据附加到python中的文件？

Question

import pickle

def user():
    name_input = raw_input("Name: ")
    age_input = raw_input("Age: ")
    email_input = raw_input("E-Mail: ")
    ph_input = raw_input("Phone Number: ")
    user_input = {'Name': name_input, 'Age': age_input, 'E-Mail': email_input, 'Phone number': ph_input}
    return user_input

a = user()
with open("picke.txt", "wb") as f:
    pickle.dump(a,f, pickle.HIGHEST_PROTOCOL)

b = "abc"
with open("picke.txt", "wb") as fi:
    pickle.dump(b,fi, pickle.HIGHEST_PROTOCOL)

When a file is opened, pickle dumped and closed.Again I open the same file to pickle.dump in it. It does not append to the file but overwrites it. Any suggestions?

Answer 1

I was looking for the same problem, and the answer provided before did not work for me, using Python3.7

My solution is opening the file in 'ab' mode, use pickle to convert your object to binary ( pickle.dumps() not pickle.dump()) and write this to the file in a second step.

with open('picke.txt', 'ab') as fi:
    bin_obj = pickle.dumps(obj)
    fi.write(bin_obj)

Hope this helps.

Answer 2

You are creating a new "picke.txt" with the lines:

with open("picke.txt", "wb") as fi:
    pickle.dump(a, f, pickle.HIGHEST_PROTOCOL)

You need to open in ab mode to append, not wb mode to write a new file as follows:

with open("picke.txt", "ab") as fi:
    pickle.dump(a, f, pickle.HIGHEST_PROTOCOL)