coauthor2.py

import couchdb
import config

couchserver = couchdb.Server("http://%s:%s@%s/" % (config.user, config.password, config.server))
pubdb = couchserver["publications"]
persondb = couchserver["persons"]

def cache_search(name):
    mango = {
        'selector': {
            'name': name
        },
        'fields': ['_id', 'co-authors'],
        'limit': 1
    }

    res = list(persondb.find(mango))[0]
    return res.get("co-authors")

def cache_results(name, co_authors):
    mango = {
        'selector': {
            'name': name
        },
        'limit': 1
    }

    res = list(persondb.find(mango))[0]
    res["co-authors"] = co_authors
    persondb[res["_id"]] = res


def level_one(name):

    cached_authors = cache_search(name)
    if cached_authors is not None:
        return cached_authors

    mango = {
        'selector': {
            'name': name
        },
        'fields': ['author-of'],
        'limit': 1
    }

    papers = list(persondb.find(mango))[0].get("author-of")
    co_authors = set()

    id_list = []

    for paper in papers:
        p = pubdb[paper]
        ids = p["authored-by"]
        id_list.extend(ids)

    co_authors = set()

    for i in id_list:
        n = persondb[i].get("name")
        co_authors.add(n)

    co_authors.remove(name)

    cache_results(name, list(co_authors))

    return list(co_authors)

def level_n_recurse(name, n):
    if n == 1:
        l = level_one(name)
        return {1: l}
    else:
        levels = level_n_recurse(name,n-1)
        candidates = set()
        for p in levels[n-1]:
            cas = level_one(p)
            candidates.update(cas)
        for i in range(1,n):
            candidates.difference_update(levels[i])
        levels[n] = list(candidates)
        return levels

def level_n(name, n):
    levels = level_n_recurse(name, n)
    return levels[n]

done = False
level = 1
while not done:
    start = "Michael J. Franklin"
    search = "Moshe Y. Vardi"
    l = level_n(start, level)
    if len(l) == 0:
        print("Not Found")
        done = True
        break
    if search in l:
        print("Found at level {}".format(level))
        done = True
        break
    level += 1