module its full name, code, load date and a Boolean indicating whether
it's a package or not.
The following simple program:
import dbimp, sys
if __name__ == "__main__":
dbimp.install()
#import bsddb.db
import a.b.c.d
import bsddb
gives a traceback from its last line. The whole output is
$ python -i test.py
Accepted *db*
found a in db
load_module: a
a loaded: <module 'a' from 'db:a'> pkg: 1
found a.b in db
load_module: a.b
a.b loaded: <module 'a.b' from 'db:a.b'> pkg: 1
found a.b.c in db
load_module: a.b.c
a.b.c loaded: <module 'a.b.c' from 'db:a.b.c'> pkg: 1
found a.b.c.d in db
load_module: a.b.c.d
a.b.c.d loaded: <module 'a.b.c.d' from 'db:a.b.c.d'> pkg: 0
found bsddb in db
load_module: bsddb
found weakref in db
load_module: weakref
weakref loaded: <module 'weakref' from 'db:weakref'> pkg: 0
Traceback (most recent call last):
File "test.py", line 7, in ?
import bsddb
File "/c/steve/Projects/Python/dbimp/dbimp.py", line 49, in load_module
exec code in module.__dict__
File "db:bsddb", line 62, in ?
File "/usr/lib/python2.4/os.py", line 133, in ?
from os.path import (curdir, pardir, sep, pathsep, defpath, extsep,
altsep,
ImportError: No module named path
It appears that for some reason execution of the code in
bsddb/__init__.pyc (loaded from the database using my importer) is
causing the os module to execute again although it has already run and
been cached in sys.modules.
Any explanations would be welcome. The importer module is shown below (a
posting with an attachment to avoid code folding didn't appear to make
it out)
Also if someone can suggest how associate the source file with
module/package code from the database that would make tracebacks look
more conventional, though I'd like to retain the indication the module
was loaded by dbimp somehow.
#
# Import modules from a database
#
import sys, db, marshal, imp, new
conn = db.conn()
curs = conn.cursor()
curs.execute("select modName from module")
impdict = {}
for n in [x[0] for x in curs.fetchall()]:
impdict[n] = 1
class dbimporter(object):
def __init__(self, item, *args, **kw):
if item != "*db*":
raise ImportError
print "Accepted", item
def find_module(self, fullname, path=None):
#print "find_module:", fullname, "from", path
if fullname not in impdict:
#print "Bailed on", fullname
return None
else:
print "found", fullname, "in db"
return self
def load_module(self, modname):
print "load_module:", modname
if modname in sys.modules:
return sys.modules[modname]
curs.execute("select modCode, modPackage from module where
modName=%s", (modname, ))
row = curs.fetchone() # should only BE one ...S
if not row:
#print modname, "not found in db"
raise ImportError, "DB module %s not found in modules"
code, package = row
code = marshal.loads(code)
module = new.module(modname)
sys.modules[modname] = module
module.__name__ = modname
exec code in module.__dict__
module.__file__ = "db:%s" % modname
module.__loader__ = dbimporter
if package:
module.__path__ = sys.path
exec code in module.__dict__
print modname, "loaded:", repr(module), "pkg:", package
return module
def install():
sys.path_hooks.append(dbimporter)
sys.path_importer_cache.clear() # probably not necessary
sys.path.insert(0, "*db*") # probably not needed with a metea-path
hook?
regards
Steve
--
Steve Holden http://www.holdenweb.com/
Python Web Programming http://pydish.holdenweb.com/
Holden Web LLC +1 703 861 4237 +1 800 494 3119