Help compare substring

example='''001computer hardwaremouse
002computer hardwaremonitor
003kitchen hardware knife
004kitchen hardware scissors
005kitchen hardware stove
006computer hardwarekeyboard
007computer hardwareplotter
'''


'''
and i want to organize it this form .... i compare all the data to organize it

computer hardware
001 mouse
002 monitor
007 keyboard

kitchen hardware
003 knife
004 scissors
'''

import string,pdb

def arrange(data,feature):
    '''
        good enough to succeed with the test data, but not much better.
    '''
    d = dict()
    for line in data.split('\n'):
        fields = line.split(feature)
        if len(fields) < 2:               # the feature doesn't appear
            next
        key = fields[0].strip()
        value = feature.join(fields[1:]).strip() # handle multiple occurrences of feature, 1sFxFyFz -> 1s:xFyFz (still missing the endswith case, 1sFxF -> 1s:x  oh well
        d[key] = value
    bln = set()                     # extract 'kitchen' and 'computer'
    #    pdb.set_trace()
    for key in d.keys():
        for (i,c,) in enumerate(key):
            if c not in string.digits:
                break
        try:
            bln.add(key[i:])
            d[key] = key[:i]+' '+d[key]       # the values of d look like the innermost level
        except:
            del d[key]
    result = []
    a = result.append
    for n in sorted(bln):
        a(n+' '+feature)
        for (key,value,) in d.items():
            if n in key:
                a(value)
        a('')
    return '\n'.join(result)

def main(filename = None,feature='hardware'):
    try:
        with open(filename,'r') as inf:
            data = inf.read()
    except:
        data = example
    print(arrange(data,feature))

if '__main__' == __name__:
    main()