conditional importing

[Steve Holden]

"Gerhard Häring" <gerhard.haering at gmx.de> wrote in message
news:mailman.1027907323.21253.python-list at python.org...
> * Scott Hathaway <slhath at charter.net> [2002-07-28 20:29 -0500]:
> > How can I do a conditional import?  I am creating a database wrapper
class
> > that is similar to adodb in PHP.
> > I have the following class:
> >
> > >from mx.ODBC import Windows as db1
> > import MySQLdb as db2
>
> Better use something like:
>
> module_name = "MySQLdb"
> try:
>     dbmodule = __import__(module_name)
> except ImportError, reason:
>     # error handling here
>
> def open_connection(*args, **kwargs):
>     return dbmodule.connect(*args, **kwargs)
>
> Unfortunately, the arguments for the connect method aren't standardized.
> But at least some modules allow for a single connection string where the
> arguments (host, user, passwd, ...) are separated by colons.
>

My preferred technique (when all modules obey the DB API sufficiently for my
needs) is:

    if dbtype == 'odbc':
        import mx.ODBC.Windows as db
    else:
        import MySQLdb as db

    conn = db.open(...)

The real problem at present appears to be the various different modules'
insistence on using different paramstyles - in the case above, mxODBC
expects a "?" for a parameter substitution, while MySQLdb expects a "%s".

something-i-need-to-work-on-ly y'rs  - steve
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Steve Holden                                 http://www.holdenweb.com/
Python Web Programming                http://pydish.holdenweb.com/pwp/
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