[Tutor] creating variables from the 'key' of a dictionary. (original) (raw)

Jeff Shannon jeff at ccvcorp.com
Fri Jul 2 15:13:22 EDT 2004

Larry Blair wrote:

I think what I want to do is create a function that would load a dictionary with all parameters from the file. Then in the original script use that dictionary in a for loop to create the variables from the key.

My question is there a way to create a variable with the name of the key in a dictionary i.e. para = {} para['sourceserver'] = 'cm05'

Yes, you can do that. The following three code fragments all result in an identical dictionary:

 para = { 'source_server':'cm05' }

 para = {}
 para['source_server'] = 'cm05'

 key = 'source_server'
 value = 'cm05'
 para = {}
 para[key] = value

In addition, there's a couple of things that might make your life even easier.

First, consider creating a Python module called settings.py, which contains the definition of your parameters dictionary:

----- settings.py ---------

para = { 'source_server':'cm05', 'target_server':'tm02', ... }

Now, in your other files, you can simply

import settings

src = settings.para['source_server'] ....

Second, if your settings are very dynamic and change often, it might be useful to investigate the shelve module. This is a library module that will essentially allow you to store the current state of a dictionary as a disk file, and to later reload that dictionary from the file. This would let you have a persistent record of the most recent state of your parameters.

Jeff Shannon Technician/Programmer Credit International

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