Create new CSV file by combining results of directory traversal + original CSV file

correlate.py

#!/usr/bin/python

import csv
import os
from datetime import datetime

skipped = open('no-target.csv', 'w')

targets = {}
with open('file_mapping.csv') as csvfile:
    reader = csv.DictReader(csvfile)
    for row in reader:
        src = os.path.basename(row['file_path'])
        dst = row['s3_path']
        targets[src] = dst

sources = {}
for root, dirs, files in os.walk("/Librarian"):
    if 'SafeToDelete' in dirs:
        dirs.remove('SafeToDelete')

    for name in files:
        path = os.path.join(root, name)
        mtime = datetime.fromtimestamp(os.path.getmtime(path))

        if name in targets:
            if not name in sources or sources[name]['mtime'] < mtime:
                sources[name] = {
                    'src': path,
                    'dst': targets[name],
                    'mtime': mtime
                }
        else:
            skipped.write(path + '\n')

with open('new-mapping.csv', 'w') as csvfile:
    writer = csv.DictWriter(csvfile, fieldnames=['src', 'dst'], extrasaction='ignore')
    for name in sources:
        writer.writerow(sources[name])