如何腌制和去腌制

Question

import  pickle
variety = ["sweet", "box", "cat"]
shape = ["back","spear", "log"]
pickleFile = open("pickle.txt", 'w')
pickle.dump(variety, pickleFile)
pickle.dump(shape, pickleFile)
pickleFile.close()

pickleFile = open("pickle.txt", 'r')
test = pickle.load(pickleFile)
shape = pickle.load(pickleFile)

print ("variety : ", test, " shape : ", shape)
pickleFile.close()

当我运行以上代码时，我得到以下错误

line 6, in <module>
pickle.dump(variety, pickleFile)
TypeError: must be str, not bytes

而且我不确定是否可以在变量 'test' 中进行 unpickling 或者不是因为我用变量 'variety'

腌制了

Answer 1

根据help(pickle.dump)，

The file argument must have a write() method that accepts a single bytes argument. It can thus be a file object opened for binary writing, a io.BytesIO instance, or any other custom object that meets this interface.

看来您必须以二进制模式打开文件。不要忘记对 loading 也做同样的事情。

import  pickle
variety = ["sweet", "box", "cat"]
shape = ["back","spear", "log"]
pickleFile = open("pickle.txt", 'wb')
pickle.dump(variety, pickleFile)
pickle.dump(shape, pickleFile)
pickleFile.close()

pickleFile = open("pickle.txt", 'rb')
test = pickle.load(pickleFile)
shape = pickle.load(pickleFile)

print ("variety : ", test, " shape : ", shape)
pickleFile.close()

结果：

variety :  ['sweet', 'box', 'cat']  shape :  ['back', 'spear', 'log']

Answer 2

您的问题是您正试图将腌制对象写入文本文件。这就像尝试用 MS word 编写数据库。

腌制文件的正确文件扩展名是“.pkl”。该文件还必须以二进制模式写入和读取。

我的建议是将文件扩展名更改为“.pkl”，然后使用两个 with 循环来整理您的代码。加载和写入的更正就像将 'w' 更改为 'wb' 一样简单，结果如下所示：

import  pickle
variety = ["sweet", "box", "cat"]
shape = ["back","spear", "log"]
with open("pickle.pkl", 'wb') as pickleFile:
    pickle.dump(variety, pickleFile)
    pickle.dump(shape, pickleFile)
    pickleFile.close()

with open("pickle.pkl", 'rb') as pickleFile:
    test = pickle.load(pickleFile)
    shape = pickle.load(pickleFile)

print ("variety : ", test, " shape : ", shape)
pickleFile.close()

如何腌制和去腌制

How to pickle and unpickle

python

pickle

python-3.x