python如何调试？

在执行shell脚本的时候，可以sh -x来显示程序运行过程，可以用来排错

在python中是否有呢？答案是肯定的

1.可以使用pdb来进行调试，举例如下

代码及运行结果如下：

[root@node100 vagrant]# cat kwargs.py 
#!/usr/bin/python
def test_kwargs(farg,*argvs,**kwargs):
    print "farg is " + farg
    for arg in argvs:
	print "another arg is " +  arg
    for key ,value in kwargs.items():
	print key + " is " + value
test_kwargs("first","second","third",name="zhaolibin",age="18")
[root@node100 vagrant]# python kwargs.py 
farg is first
another arg is second
another arg is third
age is 18
name is zhaolibin

使用pdb调试可以如下：

[root@node100 vagrant]#  python -m pdb kwargs.py 
> /home/vagrant/kwargs.py(2)<module>()
-> def test_kwargs(farg,*argvs,**kwargs):
(Pdb) s
> /home/vagrant/kwargs.py(8)<module>()
-> test_kwargs("first","second","third",name="zhaolibin",age="18")
(Pdb) s
--Call--
> /home/vagrant/kwargs.py(2)test_kwargs()
-> def test_kwargs(farg,*argvs,**kwargs):
(Pdb) s
> /home/vagrant/kwargs.py(3)test_kwargs()
-> print "farg is " + farg
(Pdb) s
farg is first
> /home/vagrant/kwargs.py(4)test_kwargs()
-> for arg in argvs:
(Pdb) s
> /home/vagrant/kwargs.py(5)test_kwargs()
-> print "another arg is " +  arg
(Pdb) s
another arg is second
> /home/vagrant/kwargs.py(4)test_kwargs()
-> for arg in argvs:
(Pdb) s
> /home/vagrant/kwargs.py(5)test_kwargs()
-> print "another arg is " +  arg
(Pdb) s
another arg is third
> /home/vagrant/kwargs.py(4)test_kwargs()
-> for arg in argvs:
(Pdb) ss
*** NameError: name 'ss' is not defined
(Pdb) s
> /home/vagrant/kwargs.py(6)test_kwargs()
-> for key ,value in kwargs.items():
(Pdb) s
> /home/vagrant/kwargs.py(7)test_kwargs()
-> print key + " is " + value
(Pdb) s
age is 18
> /home/vagrant/kwargs.py(6)test_kwargs()
-> for key ,value in kwargs.items():
(Pdb) s
> /home/vagrant/kwargs.py(7)test_kwargs()
-> print key + " is " + value
(Pdb) s
name is zhaolibin
> /home/vagrant/kwargs.py(6)test_kwargs()
-> for key ,value in kwargs.items():
(Pdb) s
--Return--
> /home/vagrant/kwargs.py(6)test_kwargs()->None
-> for key ,value in kwargs.items():
(Pdb) s
--Return--
> /home/vagrant/kwargs.py(8)<module>()->None
-> test_kwargs("first","second","third",name="zhaolibin",age="18")

2.常用的命令如下：

　　c  继续执行

　　w 显示当前正在执行的代码行的上下文

　　a 打印当前函数的参数列表

　　s 执行当前代码行，并停在第一个能停的地方（相当于单步进入）

　　n 继续执行到当前函数的下一行，或者当前行直接返回（单步跳过）

一般用s就可以了