ImportError:没有名为_sqlite3的模块

Question

我正在为Google App Engine编写代码，而我的本地测试得到了以下错误：

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Traceback (most recent call last):
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3185, in _HandleRequest
    self._Dispatch(dispatcher, self.rfile, outfile, env_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 3128, 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 2387, in Dispatch
    self._module_dict)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 2297, 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 2193, in ExecuteOrImportScript
    exec module_code in script_module.__dict__
  File "C:\Users\Chris Reade\Documents\SI 182\Final\geneticsalesman\Final.py", line 7, in <module>
    from pyevolve import DBAdapters
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1922, in load_module
    return self.FindAndLoadModule(submodule, fullname, search_path)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1824, in FindAndLoadModule
    description)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1775, in LoadModuleRestricted
    description)
  File "C:\Users\Chris Reade\Documents\SI 182\Final\geneticsalesman\pyevolve\DBAdapters.py", line 21, in <module>
    import sqlite3
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1922, in load_module
    return self.FindAndLoadModule(submodule, fullname, search_path)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1824, in FindAndLoadModule
    description)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1775, in LoadModuleRestricted
    description)
  File "C:\Python26\lib\sqlite3\__init__.py", line 24, in <module>
    from dbapi2 import *
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1922, in load_module
    return self.FindAndLoadModule(submodule, fullname, search_path)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1824, in FindAndLoadModule
    description)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1272, in Decorate
    return func(self, *args, **kwargs)
  File "C:\Program Files\Google\google_appengine\google\appengine\tools\dev_appserver.py", line 1775, in LoadModuleRestricted
    description)
  File "C:\Python26\lib\sqlite3\dbapi2.py", line 27, in <module>
    from _sqlite3 import *
ImportError: No module named _sqlite3

我的python方向有一个用于sqlite3的库文件，但我不知道为什么它找不到它。任何帮助都将不胜感激。

Answer 1

App Engine SDK会尽力在任何在real App Engine (在谷歌的服务器上)上失败的模块导入上给你错误。SQlite在后者上不受支持，所以给你错误只是软件开发工具包的一种很好的说法：“你将无法在真正的Google App Engine服务器上部署这段代码”！

Answer 2

当用户第一次想要使用sqlite3时，App engine会尝试引发错误。这并不是因为App engine (本地)不允许使用sqlite3作为备用数据库，而是因为sqlite3在生产级上不受支持。因此，App engine基于sqlite3来阻止您使用sqlite3，这样您就不会错误地部署该应用程序。

因此，要在本地App Engine中使用sqlite3，您需要将sqlite3列入白名单，如下所示：

转至C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\python\runtime\sandbox.py

打开该文件，您将发现一个常量变量_WHITE_LIST_C_MODULES，声明为：

  _WHITE_LIST_C_MODULES = [
        'array',
        '_ast',
        'binascii',
        '_bisect',
         .
         .
         .,
]

然后添加sqlite3，如下所示：

  _WHITE_LIST_C_MODULES = [
                'array',
                '_ast',
                'binascii',
                '_bisect',
                 .
                 .
                 .,
                _sqlite3,
        ]

我希望这对你有用。