[Python] You can save an object to a file by using the pickle module.

You can save the object using the pickle module

When creating a process to save dictionary type data locally in Python I was wondering, "What? How do you save it?" Since I first learned about the existence of the pickle module, I will leave it as a study note. (Finally saved in JSON)

wrap up

--The pickle module allows you to save an object in a separate file in binary format. --However, the pickle module is not recommended for use from a security point of view. --Also, the saved file is Python-specific.

About the pickle module

The pickle module allows you to save an object to a file in binary format.

The pickle module implements a binary protocol for serializing Python objects and restoring serialized objects. Python official documentation: pickle

By the way, "pickle" means "pickles". Does it come from saving objects that disappear quickly? What a cool

Try using the pickle module

File creation

You can open the file in binary write mode and save the object you want to save with pickle.dump ().

createPickle.py

import pickle

d = {"name":"ndj", "age":25, "hobby": "YouTube"}
with open("sample.pickle", mode="wb") as f:
    pickle.dump(d, f)

File reading

You can load it by opening the file in binary read mode and pickle.load.

loadPickle.py

import pickle

d = {}
with open("sample.pickle", mode="rb") as f:
    d = pickle.load(f)

Objects other than dictionary type can also be saved

By the way, objects other than dictionary type can be saved in the same way.

otherPickle.py

import pickle

def dumpPickle(fileName, obj):
    with open(fileName, mode="wb") as f:
        pickle.dump(obj, f)

dumpPickle("lst.pickle", [1,2,3,4,5])
dumpPickle("str.pickle", "helooooooo!!")
dumpPickle("int.pickle", 11114)

The same is true for reading.

otherPickle.py

import pickle

def loadPickle(fileName):
    with open(fileName, mode="rb") as f:
        return pickle.load(f)

lst = loadPickle("lst.pickle")
_str = loadPickle("str.pickle")
_int = loadPickle("int.pickle")

It seems that you need to be careful when using it

There is a warning at the top of the Pickle page in the official Python documentation.

Warning The pickle module is not secure. Only unpickle data you trust. It is possible to construct malicious pickle data which will execute arbitrary code during unpickling. Python official documentation: pickle

I'm not so confident, but if the contents of the file are code in the process of converting the contents of the file to an object, it will be executed. .. It seems that you need to be careful about the usage because it will be a problem if unintended code is executed.

reference

Python Official: Pickle