def run(app=None, server=‘wsgiref‘, host=‘127.0.0.1‘, port=8080, interval=1, reloader=False, quiet=False, plugins=None, debug=None, **kargs):
今天要学习一下bottle里是怎样打印debug信息的
run函数的倒数第二个参数是debug,默认为None
try: if debug is not None: _debug(debug)
如果设置了debug的值，且不为None,则运行_debug函数
_debug = debug
_debug函数是debug函数的别名，因为和run里的debug变量同名，为了区别，所以用_debug这个名称
def debug(mode=True): """ Change the debug level. There is only one debug level supported at the moment.""" global DEBUG if mode: warnings.simplefilter(‘default‘) DEBUG = bool(mode)
globa DEBUG这句的作用是声明DEBUG这个变量是全局变量，由于要修改它的值，如果不声明为全局变量，则会将DEBUG定义为本函数内的局部变量。
if mode: warnings.simplefilter(‘default‘)
warnings.simplefilter定义简单过滤器，如果mode为真，则warnings的过滤器为default,以下是几种过滤器参数，特别要说明的是error过滤器，如果应用了这个过滤器，一旦产生警告信息，则当成错误来处理，不再执行后面的语句。
Value | Disposition |
|---|---|
"error" | turn matching warnings into exceptions |
"ignore" | never print matching warnings |
"always" | always print matching warnings |
"default" | print the first occurrence of matching warnings for each location where the warning is issued |
"module" | print the first occurrence of matching warnings for each module where the warning is issued |
"once" | print only the first occurrence of matching warnings, regardless of location |
好了，大概用法已经看懂，再看bottle是怎样应用的
# -*- coding=utf-8 -*-
from bottle import Bottle, run
app = Bottle()
@app.route(‘/hello‘)
def hello():
raise Exception("this is my error")
return "Hello World!"
run(app, host=‘localhost‘, port=8080, reloader=True, debug=True)将debug设置为True, 并在hello函数里手工制造一个异常。
浏览器里访问http://localhost:8080/hello
结果如下：
Sorry, the requested URL ‘http://localhost:8080/hello‘ caused an error:
Internal Server Error
Exception(‘this is my error‘,)
Traceback (most recent call last):
File "C:\Python27\lib\site-packages\bottle.py", line 862, in _handle
return route.call(**args)
File "C:\Python27\lib\site-packages\bottle.py", line 1740, in wrapper
rv = callback(*a, **ka)
File "D:/myproject/bottleApp/main.py", line 8, in hello
raise Exception("this is my error")
Exception: this is my error看模板源码是怎样设置的
<body>
<h1>Error: {{e.status}}</h1>
<p>Sorry, the requested URL <tt>{{repr(request.url)}}</tt>
caused an error:</p>
<pre>{{e.body}}</pre>
%%if DEBUG and e.exception:
<h2>Exception:</h2>
<pre>{{repr(e.exception)}}</pre>
%%end
%%if DEBUG and e.traceback:
<h2>Traceback:</h2>
<pre>{{e.traceback}}</pre>
%%end
</body>注：如果debug=False，则不会输出Traceback信息，生产环境一般是要关闭的，开发的时候打开方便排错。
原文地址：http://378359.blog.51cto.com/368359/1960097
