在__init__中调用类函数

I'm writing some code that takes a filename, opens the file, and parses out some data. I'd like to do this in a class. The following code works:

我正在编写一些带有文件名的代码，打开文件并解析一些数据。我想在课堂上这样做。以下代码有效：

class MyClass():
    def __init__(self, filename):
        self.filename = filename 

        self.stat1 = None
        self.stat2 = None
        self.stat3 = None
        self.stat4 = None
        self.stat5 = None

        def parse_file():
            #do some parsing
            self.stat1 = result_from_parse1
            self.stat2 = result_from_parse2
            self.stat3 = result_from_parse3
            self.stat4 = result_from_parse4
            self.stat5 = result_from_parse5

        parse_file()

But it involves me putting all of the parsing machinery in the scope of the __init__ function for my class. That looks fine now for this simplified code, but the function parse_file has quite a few levels of indention as well. I'd prefer to define the function parse_file() as a class function like below:

但它涉及我将所有解析机制放在我班级__init__函数的范围内。对于这个简化的代码，现在看起来很好，但是函数parse_file也有很多级别的缩进。我更喜欢将函数parse_file（）定义为类函数，如下所示：

class MyClass():
    def __init__(self, filename):
        self.filename = filename 

        self.stat1 = None
        self.stat2 = None
        self.stat3 = None
        self.stat4 = None
        self.stat5 = None
        parse_file()

    def parse_file():
        #do some parsing
        self.stat1 = result_from_parse1
        self.stat2 = result_from_parse2
        self.stat3 = result_from_parse3
        self.stat4 = result_from_parse4
        self.stat5 = result_from_parse5

Of course this code doesn't work because the function parse_file() is not within the scope of the __init__ function. Is there a way to call a class function from within __init__ of that class? Or am I thinking about this the wrong way?

当然这段代码不起作用，因为函数parse_file（）不在__init__函数的范围内。有没有办法从该类的__init__中调用类函数？或者我是否以错误的方式思考这个问题？

6 个解决方案

#1

Call the function in this way:

以这种方式调用函数：

self.parse_file()

You also need to define your parse_file() function like this:

您还需要像这样定义parse_file（）函数：

def parse_file(self):

The parse_file method has to be bound to an object upon calling it (because it's not a static method). This is done by calling the function on an instance of the object, in your case the instance is self.

parse_file方法必须在调用它时绑定到对象（因为它不是静态方法）。这是通过在对象的实例上调用函数来完成的，在这种情况下，实例是self。

#2

If I'm not wrong, both functions are part of your class, you should use it like this:

如果我没错，这两个函数都是你班级的一部分，你应该像这样使用它：

class MyClass():
    def __init__(self, filename):
        self.filename = filename 

        self.stat1 = None
        self.stat2 = None
        self.stat3 = None
        self.stat4 = None
        self.stat5 = None
        self.parse_file()

    def parse_file(self):
        #do some parsing
        self.stat1 = result_from_parse1
        self.stat2 = result_from_parse2
        self.stat3 = result_from_parse3
        self.stat4 = result_from_parse4
        self.stat5 = result_from_parse5

replace your line:

替换你的行：

parse_file() 

with:

有：

self.parse_file()

#3

How about:

怎么样：

class MyClass(object):
    def __init__(self, filename):
        self.filename = filename 
        self.stats = parse_file(filename)

def parse_file(filename):
    #do some parsing
    return results_from_parse

By the way, if you have variables named stat1, stat2, etc., the situation is begging for a tuple: stats = (...).

顺便说一句，如果你有名为stat1，stat2等的变量，那么情况就是要求元组：stats =（...）。

So let parse_file return a tuple, and store the tuple in self.stats.

所以让parse_file返回一个元组，并将元组存储在self.stats中。

Then, for example, you can access what used to be called stat3 with self.stats[2].

然后，例如，您可以使用self.stats [2]访问曾经被称为stat3的内容。

#4

In parse_file, take the self argument (just like in __init__). If there's any other context you need then just pass it as additional arguments as usual.

在parse_file中，使用self参数（就像在__init__中一样）。如果您需要任何其他上下文，那么只需像往常一样将其作为附加参数传递。

#5

You must declare parse_file like this; def parse_file(self). The "self" parameter is a hidden parameter in most languages, but not in python. You must add it to the definition of all that methods that belong to a class. Then you can call the function from any method inside the class using self.parse_file

你必须像这样声明parse_file; def parse_file（self）。 “self”参数是大多数语言中的隐藏参数，但不是python中的隐藏参数。您必须将其添加到属于类的所有方法的定义中。然后，您可以使用self.parse_file从类中的任何方法调用该函数

your final program is going to look like this:

你的最终节目将如下所示：

class MyClass():
  def __init__(self, filename):
      self.filename = filename 

      self.stat1 = None
      self.stat2 = None
      self.stat3 = None
      self.stat4 = None
      self.stat5 = None
      self.parse_file()

  def parse_file(self):
      #do some parsing
      self.stat1 = result_from_parse1
      self.stat2 = result_from_parse2
      self.stat3 = result_from_parse3
      self.stat4 = result_from_parse4
      self.stat5 = result_from_parse5

#6

I think that your problem is actually with not correctly indenting init function.It should be like this

我认为你的问题实际上是没有正确缩进init函数。它应该是这样的

class MyClass():
     def __init__(self, filename):
          pass

     def parse_file():
          pass