問題描述

當我在交互式會話中運行時(在我的例子中是 ipython)，并且當前在調試器中(ipdb 或 pdb)我希望能夠從調試命名空間中將變量放入主交互式命名空間.

When I am running inside an interactive session (in my case ipython), and am currently inside a debugger (ipdb or pdb) I would like to be able to put a variable into the main interactive namespace from within the debugging namespace.

這在我的代碼崩潰但已經完成大量工作時很有用，其中一些可以挽救以節省時間(例如，從磁盤加載數據).

This is useful if my code crashes, but has already done significant work, some of which is salvageable to save time (for example, loading data from disk).

所以我想要的是這樣的，例如:

so what I'd like is something like this, for example:

>>> run -m my.module
loading data from disk...
done loading data.
processing data...
---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
...

-> 這里在處理過程中出了點問題，但是數據的加載工作正常......所以我會進入調試器檢查發生了什么，并查看 loaded_data:

-> here something goes wrong during processing, but the loading of data worked fine... so I'd go into the debugger to check out what happened, and to see the loaded_data:

>>> debug
ipdb> len(loaded_data)
100000

-> 然后我希望能夠將此變量保存到交互式命名空間中，以便在調試器外部使用，如下所示:

-> Then I would like to be able to save this variable to the interactive namespace for use outside the debugger, like so:

ipdb> save_to_interactive('loaded_data')
ipdb> exit
>>> len(loaded_data)
100000

推薦答案

您可以通過獲取對外部解釋器堆棧的引用來完成此操作框架，并寫入其框架全局變量.

You can accomplish this by getting a reference to the outer interpreter's stack frame, and writing to its frame globals.

給定一個帶有斷點的示例模塊，將我們踢到 pdb:

Given a sample module with a breakpoint that kicks us into pdb:

my_module.py:

def fun(arg):
    import pdb; pdb.set_trace()
    print arg

演示基本概念的示例:

    >>> import my_module
    >>> my_module.fun(1)
    > /Users/lukasgraf/src/stackoverflow/my_module.py(3)fun()
    -> print arg
    (Pdb) import sys
    (Pdb) sys._getframe(0)
    <frame object at 0x1032ab290>
    # this is the current frame

    (Pdb) sys._getframe(0).f_globals['__name__']
    'my_module'

    # Next outer frame
    (Pdb) sys._getframe(1).f_globals['__name__']
    'pdb'

    # etc...

    # In this example, frame 10 happens to be
    # the one from the outer interpreter
    (Pdb) sys._getframe(10).f_globals['__name__']
    '__main__'

所以這里有一個快速而骯臟的函數，它在堆棧中查找 '__name__'，在幀全局變量中具有 '__main__' 的值:

So here's a quick and dirty function that walks up the stack looking for '__name__' with a value of '__main__' in frame globals:

debughelper.py:

import sys

# Be safe and define a maximum of frames we're trying to walk up
MAX_FRAMES = 20

def save_to_interactive(dct):
    n = 0
    # Walk up the stack looking for '__name__'
    # with a value of '__main__' in frame globals
    for n in range(MAX_FRAMES):
        cur_frame = sys._getframe(n)
        name = cur_frame.f_globals.get('__name__')
        if name == '__main__':
            # Yay - we're in the stack frame of the interactive interpreter!
            # So we update its frame globals with the dict containing our data
            cur_frame.f_globals.update(dct)
            break

用法:

>>> import my_module
>>> my_module.fun('foo')
> /Users/lukasgraf/src/stackoverflow/my_module.py(3)fun()
-> print arg
(Pdb) import debughelper
(Pdb) debughelper.save_to_interactive({'mykey': 42})
(Pdb) c
foo
# We continued PDB, so we're in the outer interpreter again
>>> print mykey
42
>>>

這篇關于從 python 調試器將變量保存到交互式命名空間的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！