Problem requiring lists

Question

The current issue im facing is comes from the following scenario. I have a script that runs a commandline program to find all files of a certain extension within an specific folder, lets call these files File A. Another section of the script runs a grep command through each file for filenames within File A. What would be the best method to store what filenames are in File A and only File A, and how could I achieve it? Thanks

Answer 1

EDIT: I see you were the one who asked the previous question! Why open a new one?

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There was a recent question on this exact problem -- the structure you are modelling is a directed graph. See my answer to that question, using Python's networkx package. Using this package is a good idea if you are going to do some post-processing of the data. However, for simple situations, you could make your own data structure. Here is a sample using an adjacency list representation of a graph; it is not difficult to use an adjacency matrix instead.

from collections import defaultdict
adj_list = defaultdict( set )

for filename in os.listdir( <dir> ):
    with open( filename ) as theFile:
        for line in theFile:
            # parse line into filename, say 'target'
            adj_list[ filename ].add( target )

This will give you a dictionary of filename -> files linked by that file.