import os

vlandict={}

for fn in [ '../configs/ct/ct-noc-a8325-a.cfg' ]:
    print(os.path.basename(fn))
    with open(fn) as infile:
        for line in infile:
            if line.startswith("vlan"):
                print(line)
                vlan=line.strip()
                try:
                    vlandict[vlan].append(fn)
                except KeyError:
                    vlandict[vlan]=[]
                    vlandict[vlan].append(fn)

print(vlandict)