您将如何在python中编写@debuggable装饰器？ [英] How would you write a @debuggable decorator in python?

问题描述

在调试时，我喜欢打印出函数的所有输入和输出（我知道我需要一个更好的IDE，但幽默的是，这可以用于错误报告）。因此，我理想上希望拥有：

  @debuggable 
 def myfunc（argA，argB，argC）： 
返回argB + 1 
  

并使用全局变量打开或关闭调试。不，我猜你也不喜欢全局变量。

我能想到的最好的方法是：

  DEBUG =真
 
可调试（func）：
如果已调试：
 def装饰（* args）：
打印 Entering，func.func_name 
打印 args，args 
 ret = func（* args）
打印ret 
 return ret 
返回修饰的
 else：
 return func 
 
 @debuggable 
 def myfunc（this，that）：
返回this + that 
  

并运行：

 >>> ; myfunc（1,3）
输入myfunc 
 args（1、3）
 4 
  

我该如何改善呢？

解决方案

使用调试器。说真的装饰要跟踪的每个函数都是一个坏主意。

Python

_{（来源： winpdb.org ）}

When debugging, I like to print out all the inputs and outputs of a function (I know I need a better IDE, but humour me, this could be used for error reporting). So, I'd ideally like to have:

@debuggable
def myfunc(argA,argB,argC):
    return argB+1

and use a global variable to switch on or off debugging. No, you don't like globals either, I guessed.

The best I can come up with is:

DEBUG = True

def debuggable(func):
    if DEBUG:
        def decorated(*args):
            print "Entering ",func.func_name
            print "    args ",args
            ret = func(*args)
            print ret
            return ret
        return decorated
    else:
        return func

@debuggable
def myfunc(this,that):
    return this+that

And running:

>>> myfunc(1,3)
Entering  myfunc
   args  (1, 3)
4

How can I improve that?

解决方案

Use a debugger. Seriously. Decorating every function you want to keep track is a bad idea.

Python has a debugger included, so you don't need a good IDE.

If you don't want to use a debugger, you can use the trace function.

import sys

@sys.settrace
def trace_debug(frame, event, arg):
    if event == 'call':
        print ("calling %r on line %d, vars: %r" % 
                (frame.f_code.co_name, 
                 frame.f_lineno,
                 frame.f_locals))
        return trace_debug
    elif event == "return":
        print "returning", arg

def fun1(a, b):
    return a + b

print fun1(1, 2)

That prints:

calling 'fun1' on line 14, vars: {'a': 1, 'b': 2}
returning 3
3

Even easier would be to use Winpdb:

It is a platform independent graphical GPL Python debugger with support for remote debugging over a network, multiple threads, namespace modification, embedded debugging, encrypted communication and is up to 20 times faster than pdb.

Features:

• GPL license. Winpdb is Free Software.
• Compatible with CPython 2.3 or later.
• Compatible with wxPython 2.6 or later.
• Platform independent, and tested on Ubuntu Gutsy and Windows XP.
• User Interfaces: rpdb2 is console based, while winpdb requires wxPython 2.6 or later.

_{(source: winpdb.org)}

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