Question

So I have several lists that are the headers of variables in a data file. The setup looks like this:

headerGroup1 = ["1", "2", "3, "4", "5"]
headerGroup2 = ["6", "7", "8, "9", "10"]
headerGroup3 = ["1", "2", "3", "4", "5"]

And I have a master file that looks like this:

masterVars = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"]

I want to do three things:

• Create a list that includes all the items from masterVars in order. And I don’t know if values are unique.
• If a list item contained in headerGroupX is in the masterVars, prepend that header group to the list item.
• Dump a list that contains all 64k items into something I can manage in SPSS (sort of kidding about this one)

I think this would be simple if there were only 2 lists. The big problem I think I’m running into is what happens after you prepend data to a list item. But I’m not totally sure what I’m messing up.

EDITED:

Here is an example of what I would want to output:

newMasterFile = ["headerGroup1, headerGroup3, 1", "headerGroup1, headerGroup3, 2", etc.]

Does this make anything clearer?

Answer 1

import functools # python3 compatibility (for reduce function)

# unsorted - see 3,4 are swaped!
masterVars = ["1", "2", "4", "3", "5", "6", "7", "8", "9", "10"]

input_dict=dict(headerGroup1 = ["1", "2", "3", "4", "5"],headerGroup2 = ["6", "7", "8", "9", "10"],headerGroup3 = ["1", "2", "3", "4", "5"])

# used builtins sorted function for sorting 
new_master_file=[' '.join(j[0])+' '+j[1] for j in [functools.reduce(lambda a,b:(i in input_dict[b] and a[0]+[b] or a[0],i),input_dict,[[],i]) for i in sorted(masterVars,key=int)]]

for i in new_master_file:
    print (i)

Or do you like more readable version? 😉

PS. What is SPSS?