IPython表示类 [英] IPython representation of classes

问题描述

我正在尝试使用我创建的模块进行IPython，并且它没有显示类对象的实际表示。相反它显示类似

I was trying IPython with a module I created and it does not show the actual representation of class objects. Instead it shows something like

TheClass.__module__ + '.' + TheClass.__name__

我严重在此模块中使用元类，我有真正有意义的类表示，应该向用户显示。

I heavily use metaclasses in this module and I have really meaningful class representations that should be shown to the user.

是否有一个特定于IPython的方法我可以更改以使正确的表示形式可用而不是此命名空间，这在此应用程序中是无用的？

Is there an IPython specific method I can change to make the right representation available instead of this namespace thingy that is quite useless in this application?

或者，如果不可能，我如何自定义我的IPython版本以显示我想要的信息？

Or, if that's not possible, how can I customize my version of IPython to show the information I want?

编辑

作为补充信息，如果我得到一个类并将 __ module __ 属性更改为例如没有，当试图显示表示时，它会受到此追溯的影响：

As complementary information, if I get a class and change the __module__ attribute to e.g. None, it blows with this traceback when trying to show the representation:

Traceback (most recent call last):
  ... [Huge traceback] ...
  File "C:\Python32\lib\site-packages\IPython\lib\pretty.py", line 599, in _type_pprint
    name = obj.__module__ + '.' + obj.__name__
TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'

所以我的期望是正确的，这个函数用于显示类对象：

So my expectations were right and this function is used to show class objects:

def _type_pprint(obj, p, cycle):

我试着在课堂上自定义它但我不认为我做得对。这个模块 IPython.lib.pretty 确实有一个大字典链接类型（元类的父元素）和这个函数。

I tried customizing it in my class but I don't think I'm doing it right. This module IPython.lib.pretty does have a big dictionary linking type (the parent of metaclasses) with this function.

编辑2

我尝试过的事情：

1. 将 _repr_pretty _ 函数添加到元类中。它适用于实例但不适用于类...


2. 使用此函数 IPython.lib.pretty .for_type（typ，func）。它只更改了上面写的大字典，但没有更改 RepresentationPrinter 实例制作的副本...所以这个函数完全没用了！！


3. 调用魔术函数％pprint 。它使用所有对象的默认Python __ repr __ 禁用（或启用）这个漂亮的打印功能。这很糟糕，因为列表，字典和其他许多内容的漂亮印刷非常好。

1. Adding the _repr_pretty_ function to metaclass. It do work with instances but not with classes...
2. Using this function IPython.lib.pretty.for_type(typ, func). It only changes the big dictionary a wrote above but not the copy of it made by the RepresentationPrinter instance... So this function has no use at all?!
3. Calling the magic function %pprint. It disables (or enables) this pretty print feature, using the default Python __repr__ for all the objects. That's bad because the pretty printing of lists, dict and many others are quite nice.

第一种方法更多是我想要的东西，因为它不会影响环境并且特定于此类。

The first approach is more of what I want because it does not affect the environment and is specific for this class.

推荐答案

这只是问题。现在可以这样做：

This is just an issue with IPython 0.12 and older versions. Now is possible to do:

class A(type):
    def _repr_pretty_(cls, p, cycle):
        p.text(repr(self))

    def __repr__(cls):
        return 'This Information'

class B:   #or for Py3K: class B(metaclass=A):
    __metaclass__ = A

它会显示 B 的所需表示。

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