def mine_assoc_rules(isets, min_support=2, min_confidence=0.5):

rules = []

visited = set()

for key in sorted(isets, key=lambda k: len(k), reverse=True):

support = isets[key]

if support < min_support or len(key) < 2:

continue

for item in key:

left = key.difference([item])

right = frozenset([item])

_mine_assoc_rules(

left, right, support, visited, isets,

min_support, min_confidence, rules)

return rules

def _mine_assoc_rules(

left, right, rule_support, visited, isets, min_support,

min_confidence, rules):

if (left, right) in visited or len(left) < 1:

return

else:

visited.add((left, right))

support_a = isets[left]

confidence = float(rule_support) / float(support_a)

if confidence >= min_confidence:

rules.append((left, right, rule_support, confidence))

# We can try to increase right!

for item in left:

new_left = left.difference([item])

new_right = right.union([item])

_mine_assoc_rules(

new_left, new_right, rule_support, visited, isets,

min_support, min_confidence, rules)