ImportError: No module named _sqlite3

Question

I'm writing for the Google App Engine and my local tests are getting the following error:

-->  --> -->

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

My python direction has a lib file for sqlite3 but I can't tell why it can't find it. Any help would be greatly appreciated.

Answer 1

The App Engine SDK tries hard to give you errors on any module imports that would fail on the real App Engine (on Google's servers). SQlite is not supported on the latter, so giving you errors is just the SDK's nice way of saying "you won't be able to deploy this code on the real Google App Engine servers"!

Answer 2

App engine tries to raise an error when one wanted to use sqlite3 for the first time. This happens not because App engine (local) doesn't allow the use of sqlite3 as an alternate database, this is because the sqlite3 is not supported at a production level. So App engine is doing its based to discourage you from using the sqlite3 so that you won't mistake deploying the App with sqlite3.
So to use sqlite3 in your local App Engine, you need to white list the sqlite3 as follows:

go to C:\Program Files (x86)\Google\google_appengine\google\appengine\tools\devappserver2\python\runtime\sandbox.py
Open the file and you'll find a constant variable _WHITE_LIST_C_MODULES declared as:

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

Then add sqlite3 as follows:

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

I hope this will work for you.