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标题: Python Module_pdb_DEBUG 方法 [打印本页]

作者: 易大帅 时间: 2017-3-19 08:56
标题: Python Module_pdb_DEBUG 方法
Python Module_pdb_DEBUG 方法（Jmilk） pdbpdb 是 Python 自带的程序包，为 Python 程序提供了一种可交互的源码调试功能。主要特性包括：

设置断点
单步调试
进入函数调试
查看当前代码
查看栈片段
动态修改变量值

pdb 的 Debug 方式

pdb 可以在源码内直接使用，相当于打断点，import pdb 后，在需要调试的代码处添加写入 pdb.set_trace() 语句即可。

def pushit(): import pdb pdb.set_trace() stack.append(raw_input('Enter New String: ').strip())

通过命令行参数的形式来进行调试，EG.

python -m pdb stack_demo.py

在 Python 交互环境中调试

>>> import pdb>>> import mymodule>>> pdb.run(‘mymodule.test()’)

pdb 的调试指令

指令

解析

break [codeline] 或 b [codeline]

在 codeline 行处，设置断点

condition codeline [condition]

设置条件断点

disable [codeline]

使某一行断点失效

enable [codeline]

使某一行的断点生效

clear [codeline] 或 cl [codeline]

就是清除指定的断点,不带参数就是清除所有的断点

continue 或 c

继续执行程序

list 或 l

查看当前行上下文的代码段

next 或 n

执行下一行，但跳过函数

step 或 s

执行下一行，并进入被调用的函数

j [codeline]

跳转到前面的 codeline 行

打印当前执行点的位置

return 或 r

执行代码直到从当前函数返回

打印一个变量或参数的值

打印当前函数及参数的值

感叹号后面跟着语句，可以直接改变某个变量值

exit 或 q

中止并退出

help [command] 或 h [command]

commands 的帮助手册

示例stack_demo.py : 一个 Python 实现的栈数据结构
stack = []def pushit(): #import pdb #pdb.set_trace() stack.append(raw_input('Enter New String: ').strip())def popit(): if len(stack) == 0: print "Cannot pop from an empty stack!" else: print 'Remove [', `stack.pop()`, ']'def viewstack(): print stackCMDs = {'u':pushit, 'o':popit, 'v':viewstack}def showmenu(): pr = """ p(U)sh p(O)p (V)iew (Q)uit Enter choice: """ while True: while True: try: choice = raw_input(pr).strip()[0].lower() except (EOFError, KeyboardInterrupt, IndexError): choice = 'q' print '\nYou picked: [%s]' % choice if choice not in 'uovq': print 'Invalid option, try again' else: break if choice == 'q': break CMDs[choice]()if __name__ == '__main__': showmenu()

通过命令行参数的形式来进行调试
In [2]: !python -m pdb stack_demo.py > d:\development\python27\workspace\stack_demo.py(1)<module>()-> stack = [] # 这种方式会从第一条语句开始进入调试(Pdb) b 7 # 空白行或注释不能打断点*** Blank or comment(Pdb) b 8 # 在 codeline == 8 处打上断点Breakpoint 1 at d:\development\python27\workspace\stack_demo.py:8(Pdb) n # 下一行> d:\development\python27\workspace\stack_demo.py(3)<module>() -> def pushit():(Pdb) n # 下一行，并且跳过函数内的语句> d:\development\python27\workspace\stack_demo.py(10)<module>()-> def popit(): (Pdb) l # 列出下面的代码 3 def pushit(): 4 5 #import pdb 6 #pdb.set_trace() 7 8 B-> stack.append(raw_input('Enter New String: ').strip()) 9 10 def popit(): 11 if len(stack) == 0: 12 print "Cannot pop from an empty stack!" 13 else:(Pdb) nEnter New String: 'jmilkfan'--Return--> d:\development\python27\workspace\stack_demo.py(8)pushit()->None-> stack.append(raw_input('Enter New String: ').strip())(Pdb) w # 打印当前位置 d:\development\python27\lib\bdb.py(400)run()-> exec cmd in globals, locals <string>(1)<module>() d:\development\python27\workspace\stack_demo.py(49)<module>()-> showmenu() d:\development\python27\workspace\stack_demo.py(46)showmenu()-> CMDs[choice]()> d:\development\python27\workspace\stack_demo.py(8)pushit()->None-> stack.append(raw_input('Enter New String: ').strip())(Pdb) p stack # 输出一个变量的值["'jmilkfan'"](Pdb) !stack = ["fanguiju"] # 改变一个变量的值(Pdb) p stack['fanguiju'](Pdb) c # 继续往下执行 p(U)sh p(O)p (V)iew (Q)uit Enter choice: qYou picked: [q]The program finished and will be restarted> d:\development\python27\workspace\stack_demo.py(1)<module>()-> stack = [](Pdb) q # 退出调试

在源码内直接使用

In [8]: run stack_demo.py p(U)sh p(O)p (V)iew (Q)uit Enter choice: uYou picked: > d:\development\python27\workspace\stack_demo.py(8)pushit()-> stack.append(raw_input('Enter New String: ').strip()) # 开始进入调试，该语句的前一条语句为 pdb.set_trace()(Pdb) l 3 def pushit(): 4 5 import pdb 6 pdb.set_trace() 7 8 -> stack.append(raw_input('Enter New String: ').strip()) 9 10 def popit(): 11 if len(stack) == 0: 12 print "Cannot pop from an empty stack!" 13 else:(Pdb) j 16 # 不能跳转到还没有执行过的代码行*** Jump failed: line 16 comes after the current code block(Pdb) j 3> d:\development\python27\workspace\stack_demo.py(3)pushit()-> def pushit():(Pdb) s # 进入一个函数内部> d:\development\python27\workspace\stack_demo.py(6)pushit()-> pdb.set_trace() (Pdb) s # 还可以进入到调用函数的内部--Call--> d:\development\python27\lib\pdb.py(1250)set_trace()-> def set_trace():(Pdb) c # 继续执行代码> d:\development\python27\workspace\stack_demo.py(8)pushit()-> stack.append(raw_input('Enter New String: ').strip())(Pdb) r # 执行代码直到从当前函数返回Enter New String: 'jmilkfan'--Return--> d:\development\python27\workspace\stack_demo.py(8)pushit()->None-> stack.append(raw_input('Enter New String: ').strip())(Pdb) l 25 (V)iew 26 (Q)uit 27 28 Enter choice: """ 29 30 -> while True: 31 while True: 32 try: 33 choice = raw_input(pr).strip()[0].lower() 34 except (EOFError, KeyboardInterrupt, IndexError): 35 choice = 'q'(Pdb) c p(U)sh p(O)p (V)iew (Q)uit Enter choice: uYou picked: > d:\development\python27\workspace\stack_demo.py(8)pushit()-> stack.append(raw_input('Enter New String: ').strip())(Pdb) s--Call--> d:\development\python27\lib\site-packages\win_unicode_console\raw_input.py(71)raw_input()-> def raw_input(prompt=""):(Pdb) p pr'\n\tp(U)sh\n\tp(O)p\n\t(V)iew\n\t(Q)uit\n\t\n\tEnter choice: '(Pdb) n p(U)sh p(O)p (V)iew (Q)uit Enter choice: v> d:\development\python27\workspace\stack_demo.py(37)showmenu()-> print '\nYou picked: [%s]' % choice(Pdb) nYou picked: [v]> d:\development\python27\workspace\stack_demo.py(38)showmenu()-> if choice not in 'uovq':(Pdb) n> d:\development\python27\workspace\stack_demo.py(41)showmenu()-> break(Pdb) n> d:\development\python27\workspace\stack_demo.py(44)showmenu()-> if choice == 'q':(Pdb) n> d:\development\python27\workspace\stack_demo.py(46)showmenu()-> CMDs[choice]()(Pdb) n[u"'jmilkfan'", u"'fanguiju'", u"'fanguiju'"]> d:\development\python27\workspace\stack_demo.py(30)showmenu()-> while True:(Pdb) n> d:\development\python27\workspace\stack_demo.py(31)showmenu()-> while True:(Pdb) n> d:\development\python27\workspace\stack_demo.py(32)showmenu()-> try:(Pdb) n> d:\development\python27\workspace\stack_demo.py(33)showmenu()-> choice = raw_input(pr).strip()[0].lower()(Pdb) n p(U)sh p(O)p (V)iew (Q)uit Enter choice: v> d:\development\python27\workspace\stack_demo.py(37)showmenu()-> print '\nYou picked: [%s]' % choice(Pdb) cYou picked: [v][u"'jmilkfan'", u"'fanguiju'", u"'fanguiju'"] p(U)sh p(O)p (V)iew (Q)uit Enter choice: 0

IPython 自带的 Debug 工具 ipdb基本用法跟 pdb 一样，优点在于很 IPython 结合使用能更方便的完成一个功能，也更加清晰。
In [1]: run -d stack_demo.pyBreakpoint 1 at d:\development\python27\workspace\stack_demo.py:1NOTE: Enter 'c' at the ipdb> prompt to continue execution.> d:\development\python27\workspace\stack_demo.py(1)<module>()1---> 1 stack = [] 2 3 def pushit(): 4 5 stack.append(raw_input('Enter New String: ').strip())ipdb> hDocumented commands (type help <topic>):========================================EOF bt cont enable jump pdef psource run unta c continue exit l pdoc q s untilalias cl d h list pfile quit step upargs clear debug help n pinfo r tbreak wb commands disable ignore next pinfo2 restart u whatisbreak condition down j p pp return unalias whereMiscellaneous help topics:==========================exec pdbUndocumented commands:======================ll longlist retval rvipdb>

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