Python Web frontends to database backends

To illustrate how easy it is to build a Web frontend for a database using Python's universal database interface, here is an application for biologists.

• The application area is a system of six-letter codes used to represent bird species (and genera and families and subspecies). See the link to A robust bird code system for an explanation of how bird names are converted to codes.
• The last link on the above page, `Look up bird names and codes', uses a MySQL database backend. Try entering codes like AMEROB (for American Robin) and HARDUC (Harlequin Duck), or scientific names like Porzana carolina.
• Several major Python modules are involved in this application:
  • Two CGI scripts handle the two forms on the page. abbrlookup.cgi takes care of looking up codes, and scilookup.cgi handles lookup of scientific names.
  • Both these CGI scripts use a common module named showtaxa.py that provides a function named htmlTaxon() that displays the complete classification of a bird in HTML.
  • Module hier.py represents the system of taxonomic ranks (e.g, order, family, genus, species, etc.) used in the classification. This module is actually just an interface to a short text file, ranks, whose format is discussed on the documentation links on the base page for the six-letter code system. The hier.py module is required by the next module, txny.py.
  • Module txny.py contains the complete classification of North American birds. To the layers built on top of it, it looks like a system of persistent objects, but the persistence is provided by the MySQL layer below.
  • The txny.py layer is built on top of my Python database helper functions.
  • The database helper functions are built in turn on top of Python's universal database applications programming interface (DBAPI), version 1.0, which is discussed on the Python database topic guide.
  • To get the specific DBAPI that connects to the MySQL database engine, use:

    import MySQLdb

    which supports the DBAPI 1.0 interface.

John Shipman, john@nmt.edu Last updated: 2006/12/07 22:36:39 UT URL: http://www.nmt.edu/tcc/help/lang/python/web-db.html