pl/pyton: exceptions.ImportError: No module named email.Parser

Hi,

I need to parse e-mail messages in pl/python functions. So, I write:

dbmail=# create or replace function get_header(varchar) returns varchar
as $$
dbmail$# import email.Parser
dbmail$# parser = email.Parser.Parser()
dbmail$# message = parser.parse(args[0])
dbmail$# return message.get("From")
dbmail$# $$ language plpythonu;
CREATE FUNCTION
dbmail=#
dbmail=# select get_header(messageblk) from dbmail_messageblks;
ERROR: plpython: function "get_header" failed
DETAIL: exceptions.ImportError: No module named email.Parser

Simple pl/python functions works fine:

dbmail=# create or replace function test(varchar) returns varchar as $$
dbmail$# return args[0]
dbmail$# $$ language plpythonu;
CREATE FUNCTION
dbmail=#
dbmail=# select test('test');
test
------
test
(1 record)

Message parsing with standalone python works too:

$ cat mail.py
import sys
import email.Parser
parser = email.Parser.Parser()
message = parser.parse(sys.stdin)
print message.get("From")
$ python mail.py < mbox
test(at)mydomain(dot)com

Why can't I use "import email.Parser" in pl/python function?

--
Thanks,
Eugene Prokopiev

On Sun, Nov 27, 2005 at 06:17:06PM +0300, Eugene Prokopiev wrote:
> dbmail=# select get_header(messageblk) from dbmail_messageblks;
> ERROR: plpython: function "get_header" failed
> DETAIL: exceptions.ImportError: No module named email.Parser

Your function works here with Python 2.4.2 and PostgreSQL 8.0.4 and
8.1.0, although I had to use parser.parsestr() instead of parser.parse()
because the latter expects a file-like argument (an alternative would
be to use parse() and pass a StringIO object).

As for why the import fails, might PL/Python be using a different
version of Python than the command-line python program? What does
the following function show?

CREATE FUNCTION pyversion() RETURNS text AS $$
import sys
return sys.version + '\n' + '\n'.join(sys.path)
$$ LANGUAGE plpythonu;

Does this function show the same version and module search path as
an ordinary Python program?

python -c 'import sys; print sys.version, sys.path'

What do the following commands show?

ldd /path/to/python
ldd /path/to/plpython.so

--
Michael Fuhr

I use PostgreSQL 8.1.0 and Python 2.3.3

$ psql -U postgres test

test=# CREATE FUNCTION pyversion() RETURNS text AS $$
test$# import sys
test$# return sys.version + '\n' + '\n'.join(sys.path)
test$# $$ LANGUAGE plpythonu;
CREATE FUNCTION
test=# select pyversion();

pyversion

------------------------------------------------------
2.3.3 (#1, Jul 5 2004, 13:54:49)
[GCC 3.3.3 20040412 (ALT Linux, build 3.3.3-alt5)]
/usr/lib/python23.zip
/usr/lib/python2.3/
/usr/lib/python2.3/plat-linux2
/usr/lib/python2.3/lib-tk
/usr/lib/lib-dynload
(1 record)

test=# \q

$ python -c 'import sys; print sys.version, sys.path'
2.3.3 (#1, Jul 5 2004, 13:54:49)
[GCC 3.3.3 20040412 (ALT Linux, build 3.3.3-alt5)] ['',
'/usr/lib/python23.zip', '/usr/lib/python2.3',
'/usr/lib/python2.3/plat-linux2', '/usr/lib/python2.3/lib-tk',
'/usr/lib/python2.3/lib-dynload', '/usr/lib/python2.3/site-packages']

$ ldd /usr/bin/python
libpython2.3.so.1.0 => /usr/lib/libpython2.3.so.1.0 (0x00116000)
libpthread.so.0 => /lib/libpthread.so.0 (0x001fb000)
libdl.so.2 => /lib/libdl.so.2 (0x0024f000)
libutil.so.1 => /lib/libutil.so.1 (0x00253000)
libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0x00257000)
libm.so.6 => /lib/libm.so.6 (0x00310000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00333000)
libc.so.6 => /lib/libc.so.6 (0x0033c000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)

$ ldd /usr/lib/pgsql/plpython.so
libpython2.3.so.1.0 => /usr/lib/libpython2.3.so.1.0 (0x0011f000)
libpthread.so.0 => /lib/libpthread.so.0 (0x00204000)
libdl.so.2 => /lib/libdl.so.2 (0x00258000)
libutil.so.1 => /lib/libutil.so.1 (0x0025c000)
libm.so.6 => /lib/libm.so.6 (0x00260000)
libc.so.6 => /lib/libc.so.6 (0x00283000)
/lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x80000000)

Python versions are the same

--
Thanks,
Eugene Prokopiev

[Forwarding this message to the list so the resolution gets into
the archives.]

On Mon, Nov 28, 2005 at 09:00:56PM +0300, Eugene Prokopiev wrote:
> The problem with pl/python was in my configuration. My Linux (ALT Linux)
> install PostgreSQL into chroot by default, so I need to copy some python
> libs into chroot too.

--
Michael Fuhr