2010-03-06 48 views
9

当我的代码全部在一个文件中时,它工作正常。现在,我将课程分成不同的模块。这些模块被赋予与类相同的名称。也许这是一个问题,因为MainPage在加载时失败。它是否认为我试图从模块继承?模块/类名称空间冲突是否可以发生?Python:Classname与文件/模块名称相同导致继承问题?

MainPage.py

import BaseHandler 
from models import Item 
from Utils import render 

class MainPage(BaseHandler): 
    def body(self, CSIN=None): #@UnusedVariable 
     self.header('Store') 
     items = Item.all().order('name').fetch(10) 
     render('Views/table.html', self, {'items': items}) 
     self.footer() 

BaseHandler.py

from google.appengine.ext import webapp 
from google.appengine.api import users 
from Utils import * 

# Controller 
class BaseHandler(webapp.RequestHandler): 
    # ... continues ... 

失败回溯:

Traceback (most recent call last): 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3180, in _HandleRequest 
    self._Dispatch(dispatcher, self.rfile, outfile, env_dict) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3123, in _Dispatch 
    base_env_dict=env_dict) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 515, in Dispatch 
    base_env_dict=base_env_dict) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2382, in Dispatch 
    self._module_dict) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2292, in ExecuteCGI 
    reset_modules = exec_script(handler_path, cgi_path, hook) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2188, in ExecuteOrImportScript 
    exec module_code in script_module.__dict__ 
    File "C:\Users\odp\workspace\Store\src\Main.py", line 5, in <module> 
    import MainPage 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1267, in Decorate 
    return func(self, *args, **kwargs) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1917, in load_module 
    return self.FindAndLoadModule(submodule, fullname, search_path) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1267, in Decorate 
    return func(self, *args, **kwargs) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1819, in FindAndLoadModule 
    description) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1267, in Decorate 
    return func(self, *args, **kwargs) 
    File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1770, in LoadModuleRestricted 
    description) 
    File "C:\Users\odp\workspace\Store\src\MainPage.py", line 10, in <module> 
    class MainPage(BaseHandler): 
TypeError: Error when calling the metaclass bases 
    module.__init__() takes at most 2 arguments (3 given) 

更新我似乎解决了它。这个导入效果好多了:

from BaseHandler import BaseHandler 

让模块和类名相同是不好的样式吗?

+6

只要套管截然不同,只要模块和类名相同,这种风格并不差。在Python中,约定模块名称全部为小写,类名称为CamelCase。我建议你阅读Python风格指南(PEP 8) - http://www.python.org/dev/peps/pep-0008/。这非常有帮助! – jathanism 2010-03-06 18:29:56

回答

17

是的,模块名称与其他所有模块名称共享相同的名称空间,并且,Python认为您正尝试从模块继承。

变化:

class MainPage(BaseHandler): 

到:

class MainPage(BaseHandler.BaseHandler): 

,你应该是好去。这样,你就说“请从BaseHandler模​​块中的BaseHandler类继承”。

或者,你可以改变:

import BaseHandler 

到:

from BaseHandler import BaseHandler 
16

首先所有的文件名应该是全部小写。这是Python的惯例,至少在大多数情况下有助于避免这种混淆。

接下来,您从MainHandler.py导入是错误的。您正在导入BaseHandler(该模块),并将其引用为类。这个班级实际上是BaseHandler.BaseHandler。你需要像这样引用它。

试试看,它应该适合你。

+8

+1为小写的文件名提示 – 2011-11-16 07:18:09

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