mxCrypto is an extension package that provides OO-style access to the cipher algorithms and hash functions included in OpenSSL/SSLeay, a very nifty cryptographic library originally written by Eric Young and now maintained by the OpenSSL team. Its main purpose is filling in the missing parts in Andrew Kuchling's pycrypt export package with high quality implementations. Due to the ITAR export restrictions on cryptographic software, Andrew's implementations are not legally downloadable from outside the US.
python-ldap provides an object-oriented API to access LDAP directory servers from Python programs. Mainly, it wraps the OpenLDAP 2.3+ libs for that purpose. Additionally, the package contains modules for other LDAP-related stuff (such as processing LDIF, LDAPURLs, and LDAPv3 schema).
Y Object Database Adapter (YODA) is an environment for creating and running network accessible applications. It can permanently store objects of any type and complexity, and supports attributes of most types (with the exception of only a few Python types, such as thread locks). It can be extended with YODA- server applications, and an application compiler and loader are provided.
dnspython is a DNS toolkit for Python. It supports almost all of the record types. It can be used for queries, zone transfers, and dynamic updates. It supports TSIG authenticated messages and EDNS0. dnspython provides both high and low level access to DNS. The high level classes perform queries for data of a given name, type, and class, and return an answer set. The low level classes allow direct manipulation of DNS zones, messages, names, and records.
pywrat (Python Wrappers for Remote Access Tools) is a set of wrappers that can be used for accessing remote hosts. They use ssh and scp for remote shell and file system access and can be used as a generalized access method with a single configuration file for all host, user, and key setups. The wrappers are intended to simplify remote access in shell scripts, but it is also possible to use the wrapper modules directly from Python programs.