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I've been searching on this but am coming up a little short on exactly how to do specifically what i am trying to do.. I want to concatentate a string (I guess it would be a string in this case as it has a variable and string) such as below, where I need to use a variable consisting of a string to call a listname that has an index (from another variable).. I simplified my code below to just show the relevant parts its part of a macro that is replacing values:

toreplacetype = 'type'
toreplace_indx = 5
replacement_string = 'list'+toreplacetype[toreplace_indx]

so... I am trying to make the string on the last line equal to the actual variable name:

replacement_string = listtype[5]

Any advice on how to do this is appreciated

EDIT:

To explain further, this is for a macro that is sort of a template system where I am indicating things in a python script that I want to replace with specific values so I am using regex to do this. So, when I match something, I want to be able to replace it from a specific value within a list, but, for example, in the template I have {{type}}, so I extract this, but then I need to manipulate it as above so that I can use the extracted value "type" to call a specific value from within a list (such as from a list called "listtype") (there is more than 1 list so I need to find the one called "listtype" so I just want to concatenate as above to get this, based on the value I extracted using regex

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  • I'm trying to be sure of ignacio's method below, would this be correct: vars = {'list':'list'+toreplacetype}; replacement_string = vars['list'][5] ? Commented Aug 25, 2010 at 2:58

3 Answers 3

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This is not recommended. Use a dict instead.

vars['list%s' % toreplacetype][5] = ...
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5 Comments

could you elaborate a bit more, I'm not sure exactly how I could use this to call a list, such as a list called "listtype" (with index5)
vars = {} ; vars['listtype'] = []
I guess I'm just not following how this relates to my question, i do appreciate your help in this though
Rick, what I think Ignacio is saying is that you could create a dictionary key listtype, with the value of the actual list. It would mean less obscure workarounds.
now that I played around with this more I get what Ignacio meant and this seems the easiest way to do this, it was just a matter of rethinking what I was trying to do in terms of using a dictionary in that way.. thanks for pointing me in the right direction ignacio and then tim for clarifying it so that I could act on it
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Hrm...

globals()['list%s'% toreplacetype][toreplace_indx]
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Ok, it seems these types of things keep coming back to globals() or locals() for me so I guess in python this is the way to do this sort of thing, I will study globals in more depth then to learn the ins and outs of it
globals just returns a dict of objects in the global scope. I recommend using Ignacio's method, because it avoids the global namespace..
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replacement_string = 'list'+toreplacetype+'['+str(toreplace_indx)+']'

will yield listtype[5] when you print it.

You need to basically break it into 5 parts: 1 string variable, 3 strings and an int casted to a string.

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I should have mentioned more about this I guess.. (I will edit above to explain more).. I want this: 'list'+toreplacetype[toreplace_indx] to equal the variable name of listtype[5]

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