Where:
http://docs.python.org/lib/module-bsddb.html


You say there:
<quote>
btopen(  	filename[, flag[, mode[, btflags[,
cachesize[, maxkeypage[, minkeypage[, psize[,
lorder]]]]]]]])
</quote>

the word psize should be replaced with pgsize.

An example would help:
>>> d = bsddb.btopen(None, "c", cachesize=768000,
pgsize=65536)
>>> d = bsddb.btopen(None, "n", cachesize=768000,
pgsize=65536)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "/usr/lib/python2.3/bsddb/__init__.py", line
201, in btopen
    flags = _checkflag(flag, file)
  File "/usr/lib/python2.3/bsddb/__init__.py", line
249, in _checkflag
    if os.path.isfile(file):
  File "/usr/lib/python2.3/posixpath.py", line 200, in
isfile
    st = os.stat(path)
TypeError: coercing to Unicode: need string or buffer,
NoneType found
>>> 

The latter is I believe possibly a bug in the python
wrapper not handling 'n' properly. 

Logged In: YES 
user_id=11375

I've fixed the documentation to use the right parameter
name; thanks for reporting this!

The example you give doesn't work for me: it reports
'bsddb._db.DBInvalidArgError: (22, 'Invalid argument --
set_cachesize: method meaningless in shared environment')'
with the current CVS head.  Removing the cachesize argument
makes it work.

The 'n' problem does seem to be a bug; the code should check
that file is not None before doing os.file.exists(). 
Reassigning and reclassifying the bug.

Logged In: YES 
user_id=413

fix for the 'n' flag not working with a filename of None
committed (with a test case).  svn rev 45318.