ANN: Pyme -- Python OO interface to GPGME

John Goerzen jgoerzen at
Tue Nov 19 23:01:01 CET 2002


Today I am announcing the first release of Pyme, the brand-new Python
bindings for GPGME.  Pyme:

 * Provides a convenient class-based interface to GPGME functions;
 * Exists and is supported;
 * Supports most GPGME functions automatically by reflection; thus,
   no code changes will be necessary to support most new GPGME features
 * Supports callbacks written in Python.
 * Features easy installation:  python build; python install
 * Provides pre-built .debs for Debian GNU/Linux users.

You may obtain Pyme at

The following is from the Pyme documentation:

Welcome to PyME, the GPGME Interface for Python.  "Pyme", when prounced,
rhymes with "Pine".

The latest release of this package may be obtained from


 * Feature-rich, full implementation of the GPGME library.  Supports
   all GPGME features except interactive editing (coming soon).
   Callback functions may be written in pure Python.

 * Ability to sign, encrypt, decrypt, and verify data.

 * Ability to list keys, export and import keys, and manage the keyring.

 * Fully object-oriented with convenient classes and modules.


For those of you familiar with GPGME, you will be right at home here.

Pyme is, for the most part, a direct interface to the C GPGME
library.  However, it is re-packaged in a more Pythonic way --
object-oriented with classes and modules.  Take a look at the classes
defined here -- they correspond directly to certain object types in GPGME
for C.  For instance, the following C code:

GpgmeCtx context;
GpgmeRecipients recp;
gpgme_op_encrypt(context, recp, plain, cipher);

Translates into the following Python code:

context = core.Context()
recp = core.Recipients()
context.encrypt(recp, plain, cipher)

The Python module automatically does error-checking and raises Python
exceptions when GPGME signals an error.  Those exceptions correspond
directly to GPGME errors.  All GPGME exceptions are defined in the
gpgme.errors module, and pyme.errors.GPGMEError is the parent of all

This documentation only covers a small subset of available GPGME functions and
methods.  Please consult the documentation for the C library
(available in doc/gpgme in this distribution) for comprehensive coverage.

This library uses Python's reflection to automatically detect the methods
that are available for each class, and as such, most of those methods
do not appear explicitly anywhere.

This program is not for serious encryption, but for example purposes only!

import sys
from pyme import core, constants
import pyme.constants.validity

# Set up our input and output buffers.

plain = core.Data('This is my message.')
cipher = core.Data()

# Initialize our context.

c = core.Context()

# Set up the recipients.

sys.stdout.write("Enter name of your recipient: ")
name = sys.stdin.readline().strip()
r = core.Recipients()
r.add(name, constants.validity.FULL)

# Do the encryption.

c.op_encrypt(r, plain, cipher)

Note that although there is no explicit error checking done here, the
Python GPGME library is automatically doing error-checking, and will
raise an exception if there is any problem.

This program is in the Pyme distribution as examples/  The examples
directory contains more advanced samples as well.

PYME homepage:
GPGME documentation:
GPGME homepage:

Base classes: pyme.core (START HERE!)
Auxiliary classes: pyme.aux
Utilities: pyme.util
Error classes: pyme.errors
Constants: pyme.constants
Version information: pyme.version

Base classes are documented at pyme.core and auxiliary classes at pyme.aux

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