python pdb 调试

python pdb调试

在交互环境中通常使用pdb.run来调试：

import pdb

def pdb_test(arg):
   for i in range (arg):
       print (i)
   return arg

pdb.run( "pdb_test(3)" )

b 函数名、行号：

     打断点，b可以查询所有的断点。

(Pdb) b pdb_test
Breakpoint 1 at c:\users\plpcc\desktop\pdbtest.py: 3
(Pdb) b
Num Type         Disp Enb   Where
1   breakpoint   keep yes   at c:\users\plpcc\desktop\pdbtest.py: 3

  c：

     运行程序，直到遇到断点。

(Pdb) c
> c:\users\plpcc\desktop\pdbtest.py( 4 )pdb_test()
- > for i in range (arg):

   l：

     查看断点周围的代码

(Pdb) l
 1     import pdb
 2
 3 B   def pdb_test(arg):
 4  - >      for i in range (arg):
 5             print (i)
 6         return arg
 7
 8     pdb.run( "pdb_test(3)" )

  a:

     查看参数

(Pdb) a
arg = 3

  s, n：

     单步运行,区别s会进入路径中的函数，n不会进入

  p：

     查看表达式的值

(Pdb) p i
0

  condition：

     条件断点，只有条件为true断点才命中

> c:\users\plpcc\desktop\pdbtest.py( 5 )pdb_test()
- > print (i)
(Pdb) l
 1     import pdb
 2
 3     def pdb_test(arg):
 4         for i in range (arg):
 5 B - >          print (i)
 6         return arg
 7
 8     pdb.run( "pdb_test(3)" )
[EOF]
(Pdb) b
Num Type         Disp Enb   Where
2   breakpoint   keep yes   at c:\users\plpcc\desktop\pdbtest.py: 5
(Pdb) condition 2 i = = 1   / / i = = 1 时才触发断点 2
New condition set for breakpoint 2.
(Pdb) b
Num Type         Disp Enb   Where
2   breakpoint   keep yes   at c:\users\plpcc\desktop\pdbtest.py: 5
   stop only if i = = 1
(Pdb) c
0                       / / i = = 0 直接打印未断住
> c:\users\plpcc\desktop\pdbtest.py( 5 )pdb_test()
- > print (i)             / / 触发断点，i = = 1
(Pdb) p i
1

  bt:

      查看调用堆栈

(Pdb) bt
 c:\python33\lib\bdb.py( 405 )run()
- > exec (cmd, globals , locals )
 ( 1 )()
> c:\users\plpcc\desktop\pdbtest.py( 5 )pdb_test()
- > print (i)

  r：

      执行到函数返回

(Pdb) r
1
2
- - Return - -
> c:\users\plpcc\desktop\pdbtest.py( 6 )pdb_test() - > 3 / / 代码位置、函数返回值 - > 3
- > return arg                                       / / 代码位置的语句
(Pdb) l
 1     import pdb
 2
 3     def pdb_test(arg):
 4         for i in range (arg):
 5             print (i)
 6  - >      return arg
 7
 8     pdb.run( "pdb_test(3)" )

通过pdb.set_trace() 在代码中指定位置嵌入一个断点，通常可以通过调试开关来控制

import pdb

__DEBUG__ = True

def pdb_test(arg):
   if True = = __DEBUG__:
       pdb.set_trace()
   for i in range (arg):
       print (i)
   return arg

pdb_test( 3 )

运行后在pdb.set_trace()位置被断住，当__DEBUG__ = False，代码正常运行

> c:\users\plpcc\desktop\pdbtest.py( 8 )pdb_test()
- > for i in range (arg):
(Pdb) l
 3     __DEBUG__ = True
 4
 5     def pdb_test(arg):
 6         if True = = __DEBUG__:
 7             pdb.set_trace()
 8  - >      for i in range (arg):
 9             print (i)
10         return arg
11
12     pdb_test( 3 )
[EOF]

通过pdb.pm()进行事后调试，可以跟踪异常程序最后的堆载信息：

Traceback (most recent call last):
 File "C:\Users\plpcc\Desktop\pdbTest.py" , line 13 , in
   pdb_test( 3 )
 File "C:\Users\plpcc\Desktop\pdbTest.py" , line 10 , in pdb_test
   1 / 0
ZeroDivisionError: division by zero
>>> import pdb
>>> pdb.pm()
> c:\users\plpcc\desktop\pdbtest.py( 10 )pdb_test()
- > 1 / 0
(Pdb) l
 5     def pdb_test(arg):
 6         if True = = __DEBUG__:
 7             pdb.set_trace()
 8         for i in range (arg):
 9             print (i)
10  - >          1 / 0
11         return arg
12
13     pdb_test( 3 )