path processing

gistfile1.py

# [string] -> [[path component]]
components = lambda lines: map(lambda s: s.split('/')[1:], map(lambda s: s.strip(), lines))

# [component] -> {c1: {c2: {c3: ...}}}
rawtree = lambda x: reduce(lambda l,k: {k:l if type(l) is dict else {l:{}}}, x[::-1], {})

# [{c1: {c2: a}, {c1: {c3: a}] -> {c1: {c2: a c3: a}}
reducefn = lambda t,e: (lambda key=e.keys()[0]: (lambda oval=t.get(key): \
        dict( \
            filter(lambda i: i[0] != key, t.items()) + [ \
                (key, filter(None, \
                    (oval if type(oval) is list else [oval]) + [e[key]])) \
                ]\
        ) \
))()()

# reducefn recursively
walk = lambda list_: dict( map(lambda i: (i[0], walk(i[1])), reduce(reducefn, list_, {}).items() ) )

"""
In [1]: from commands import getoutput as go

In [2]: import t as paths

In [3]: components = paths.components([s.strip() for s in go('find ./www/_build').split('\n')])

In [4]: paths.walk(map(paths.rawtree, components))
Out[4]:
{'www': {'_build': {'2011': {'05': {'06': {'up-and-running': {'index.html': {}}}}},
                    'feed.atom': {},
                    'index.html': {},
                    'static': {'favicon.ico': {}, 'style.css': {}},
                    'tag': {'org': {'index.html': {}}}}}}
"""