traceback模块被用来跟踪异常返回信息. 如下例所示:import traceback try: raise SyntaxError, "traceback test" except: traceback.print_exc()将会在控制台输出类似结果:Traceback (most recent call last): File "H:\PythonWorkSpace\Test\src\TracebackTest.py", line 3,...
traceback模块被用来跟踪异常返回信息. 如下例所示:
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import traceback try : raise SyntaxError, "traceback
test" except : traceback.print_exc() |
将会在控制台输出类似结果:
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Traceback
(most recent call last): File
"H:\PythonWorkSpace\Test\src\TracebackTest.py", line 3, in <module> raise
SyntaxError, "traceback test" SyntaxError:
traceback test |
类似在你没有捕获异常时候, 解释器所返回的结果.
你也可以传入一个文件, 把返回信息写到文件中去, 如下:
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import traceback import StringIO try : raise SyntaxError, "traceback
test" except : fp = StringIO.StringIO() #创建内存文件对象 traceback.print_exc( file = fp) message = fp.getvalue() print message |
这样在控制台输出的结果和上面例子一样,traceback模块还提供了extract_tb函数来格式化跟踪返回信息, 得到包含错误信息的列表, 如下:
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import traceback import sys def tracebacktest(): raise SyntaxError, "traceback
test" try : tracebacktest() except : info = sys.exc_info() for file ,
lineno, function, text in traceback.extract_tb(info[ 2 ]): print file , "line:" ,
lineno, "in" ,
function print text print "**
%s: %s" % info[: 2 ] |
控制台输出结果如下:
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H:\PythonWorkSpace\Test\src\TracebackTest.py
line: 7 in <module> tracebacktest() H:\PythonWorkSpace\Test\src\TracebackTest.py
line: 5 in tracebacktest raise
SyntaxError, "traceback test" **
<type 'exceptions.SyntaxError'>: traceback test |
test1.py中,当分母为0的时候,调用系统退出。代码如下:
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#!/usr/bin/python import sys def division(a = 1 ,
b = 1 ): if b = = 0 : print 'b
eq 0' sys.exit( 1 ) else : return a / b |
test2.py中,用try..except捕获异常,然后traceback.print_exc()打印。
代码如下:
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#!/usr/bin/python import sys import traceback import test1 a = 10 b = 0 try : print test1.division(a,b) except : print 'invoking
division failed.' traceback.print_exc() sys.exit( 1 ) |
执行test2.py失败抛出异常。
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$python
test2.py execution
python-2.5.1/python (enodeb/linux) b
eq 0 invoking
division failed. Traceback
(most recent call last): File
"test2.py", line 10, in <module> test1.division(a,b) File
"/home/fesu/test1.py", line 6, in division sys.exit(1) SystemExit:
1 |