Axiom should use stdlib sqlite3 on PyPy 2.0 and beyond about axiom

[divmod-migration]

(by mithrandi)
I don't think this matters on PyPy; does pysqlite2 even work there at all? On the other hand, on CPython, if pysqlite2 is installed, it seems likely that you want to use it in preference to the stdlib version.

[divmod-migration]

(by lvh)
Pretty sure it does:

======== SNIP SNIP ========
tmp ❯ virtualenv -p pypy pypy-pysqlite2 && source pypy-pysqlite2/bin/activate && pip install pysqlite
Running virtualenv with interpreter /usr/local/bin/pypy
New pypy executable in pypy-pysqlite2/bin/pypy
Installing setuptools............done.
Installing pip...............done.
Downloading/unpacking pysqlite
Using download cache from /Users/lvh/.pip/cache/https%3A%2F%2Fpysqlite.googlecode.com%2Ffiles%2Fpysqlite-2.6.3.tar.gz
Running setup.py egg_info for package pysqlite

Installing collected packages: pysqlite
Running setup.py install for pysqlite
building 'pysqlite2.sqlite' extension
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/module.c -o build/temp.macosx-10.8-x86_64-2.7/src/module.o
src/module.c:132:10: warning: 'sqlite3_enable_shared_cache' is deprecated: first deprecated in OS X 10.7 [-Wdeprecated-declarations]
rc = sqlite3_enable_shared_cache(do_enable);
^
/usr/include/sqlite3.h:4671:16: note: 'sqlite3_enable_shared_cache' declared here
SQLITE_API int sqlite3_enable_shared_cache(int) __OSX_AVAILABLE_BUT_DEPRECATED(__MAC_10_0, __MAC_10_7, __IPHONE_2_0, __IPHONE_5_0);
^
1 warning generated.
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/connection.c -o build/temp.macosx-10.8-x86_64-2.7/src/connection.o
src/connection.c:597:43: warning: passing 'const char *' to parameter of type 'char *_' discards qualifiers in nested pointer types [-Wincompatible-pointer-types]
if (PyObject_AsCharBuffer(py_val, &buffer, &buflen) != 0) {
^~~~~~~
/Users/lvh/tmp/pypy-pysqlite2/include/pypy_decl.h:278:62: note: passing argument to parameter 'arg1' here
PyAPI_FUNC(int) PyObject_AsCharBuffer(PyObject _arg0, char *arg1, Py_ssize_t arg2);
^
1 warning generated.
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/cursor.c -o build/temp.macosx-10.8-x86_64-2.7/src/cursor.o
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/cache.c -o build/temp.macosx-10.8-x86_64-2.7/src/cache.o
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/microprotocols.c -o build/temp.macosx-10.8-x86_64-2.7/src/microprotocols.o
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/prepare_protocol.c -o build/temp.macosx-10.8-x86_64-2.7/src/prepare_protocol.o
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/statement.c -o build/temp.macosx-10.8-x86_64-2.7/src/statement.o
src/statement.c:179:50: warning: passing 'const char *' to parameter of type 'char *' discards qualifiers in nested pointer types [-Wincompatible-pointer-types]
if (PyObject_AsCharBuffer(parameter, &buffer, &buflen) == 0) {
^~~~~~~
/Users/lvh/tmp/pypy-pysqlite2/include/pypy_decl.h:278:62: note: passing argument to parameter 'arg1' here
PyAPI_FUNC(int) PyObject_AsCharBuffer(PyObject *arg0, char *_arg1, Py_ssize_t *arg2);
^
1 warning generated.
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/util.c -o build/temp.macosx-10.8-x86_64-2.7/src/util.o
cc -arch x86_64 -fPIC -Wimplicit -DMODULE_NAME="pysqlite2.dbapi2" -DSQLITE_OMIT_LOAD_EXTENSION=1 -I/Users/lvh/tmp/pypy-pysqlite2/include -c src/row.c -o build/temp.macosx-10.8-x86_64-2.7/src/row.o
cc -shared -undefined dynamic_lookup -arch x86_64 build/temp.macosx-10.8-x86_64-2.7/src/module.o build/temp.macosx-10.8-x86_64-2.7/src/connection.o build/temp.macosx-10.8-x86_64-2.7/src/cursor.o build/temp.macosx-10.8-x86_64-2.7/src/cache.o build/temp.macosx-10.8-x86_64-2.7/src/microprotocols.o build/temp.macosx-10.8-x86_64-2.7/src/prepare_protocol.o build/temp.macosx-10.8-x86_64-2.7/src/statement.o build/temp.macosx-10.8-x86_64-2.7/src/util.o build/temp.macosx-10.8-x86_64-2.7/src/row.o -lsqlite3 -o build/lib.macosx-10.8-x86_64-2.7/pysqlite2/_sqlite.pypy-20.so

Successfully installed pysqlite
Cleaning up...
======== SNIP SNIP ========

After which:

======== SNIP SNIP ========
(pypy-pysqlite2)tmp ❯ python
Python 2.7.3 (b9c3566aa017, May 09 2013, 15:27:31)
[PyPy 2.0.0 with GCC 4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.27)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
And now for something completely different: ``today we're faster than yesterday
(usually)''

from pysqlite2 import dbapi2 as sqlite3
db = sqlite3.connect("test.db")
db.execute("SELECT * FROM sqlite_master")
<pysqlite2.dbapi2.Cursor object at 0x0000000103c89c20>
list(_)
[]

======== SNIP SNIP ========

Plus, sqlite3 on PyPy versions previous to 2.0 are, IIUC, pretty much just the same as they are on CPython :-) That is, cpyext's Python.h fakes CPython sufficiently well that the extension just works. However, this is the C API DBAPI2 sqlite thing, and you really want the stdlib one, because it's faster and better :)

[divmod-migration]

(by exarkun)
I don't understand the issue. If you want to use stdlib sqlite3, then don't install pysqlite2?

[divmod-migration]

(by lvh)
That doesn't appear to work, at least not when I'm pip-installing PyPI-released version of axiom. Redacted output follows, unredacted output in gist: https://gist.github.com/lvh/5999347

tmp ❯ pypy --version && virtualenv pypyvenv -p pypy && source pypyvenv/bin/activate
Python 2.7.3 (5acfe049a5b0, May 21 2013, 13:47:22)
[PyPy 2.0.2 with GCC 4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.28)]
Running virtualenv with interpreter /usr/local/bin/pypy
...
(pypyvenv)tmp ❯ pip install Twisted && pip install Epsilon && pip install Axiom
Downloading/unpacking Twisted
...
Downloading/unpacking Epsilon
...
Downloading/unpacking Axiom
(pypyvenv)tmp ❯ python
Python 2.7.3 (5acfe049a5b0, May 21 2013, 13:47:22)
[PyPy 2.0.2 with GCC 4.2.1 Compatible Apple LLVM 4.2 (clang-425.0.28)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
And now for something completely different: ``it's Sunday, again''

from axiom import store
Traceback (most recent call last):
File "", line 1, in
File "/Users/lvh/tmp/pypyvenv/site-packages/axiom/store.py", line 28, in
from axiom._pysqlite2 import Connection
File "/Users/lvh/tmp/pypyvenv/site-packages/axiom/_pysqlite2.py", line 11, in
from pysqlite2 import dbapi2
ImportError: No module named pysqlite2
from axiom import version; version
Version('axiom', 0, 6, 0)

[divmod-migration]

(by exarkun)
trunk@HEAD tries pysqlite2 and falls back to sqlite3. However this appears to be unreleased behavior, so when pip install finds the older version, the above failure is encountered.

Please try with trunk@HEAD!

[divmod-migration]

(by lvh)
So, apparently, the released version of Axiom (0.6.0) doesn't have this behavior, trunk does. This makes this ticket less important: people using PyPy are probably less likely to have pysqlite2 installed, plus, not installing pysqlite2 is easier than installing it :)