相关疑难解决方法(0)

如何使Python类可序列化？

一个简单的课程:

class FileItem:
    def __init__(self, fname):
        self.fname = fname

我该怎么做才能得到输出:

>>> import json

>>> my_file = FileItem('/foo/bar')
>>> json.dumps(my_file)
TypeError: Object of type 'FileItem' is not JSON serializable

没有错误(__CODE__)

我正在尝试创建类实例的JSON字符串表示并且有困难.假设这个类是这样构建的:

class testclass:
    value1 = "a"
    value2 = "b"

对json.dumps的调用是这样的:

t = testclass()
json.dumps(t)

它失败并且告诉我测试类不是JSON可序列化的.

TypeError: <__main__.testclass object at 0x000000000227A400> is not JSON serializable

我也尝试过使用pickle模块:

t = testclass()
print(pickle.dumps(t, pickle.HIGHEST_PROTOCOL))

它提供类实例信息,但不提供类实例的序列化内容.

b'\x80\x03c__main__\ntestclass\nq\x00)\x81q\x01}q\x02b.'

我究竟做错了什么？

class gpagelet:
    """
    Holds   1) the pagelet xpath, which is a string
            2) the list of pagelet shingles, list
    """
    def __init__(self, parent):
        if not isinstance( parent, gwebpage):
            raise Exception("Parent must be an instance of gwebpage")
        self.parent = parent    # This must be a gwebpage instance
        self.xpath = None       # String
        self.visibleShingles = [] # list of tuples
        self.invisibleShingles = [] # list of tuples
        self.urls = [] # list of string

class gwebpage:
    """
    Holds all the datastructure after …