example.py

""" a small example for finding intervals
"""
from pprint import pprint
# Data are sorted already by user and date
data = [
    [ 'user1', '2016/1', 1, 15 ],
    [ 'user1', '2016/2', 1, 15 ],
    [ 'user1', '2016/3', 1, 15 ],
    [ 'user1', '2016/6', 1, 15 ],
    [ 'user1', '2016/7', 1, 15 ],
    [ 'user1', '2016/8', 1, 15 ],
    [ 'user2', '2016/3', 1, 15 ],
    [ 'user2', '2016/6', 1, 15 ],
    [ 'user2', '2016/7', 1, 15 ],
]

periods = []
current_period = None

for line in data: 
    user, date, status, amount = line
    year, month = map (int, date.split('/'))

    if not current_period: 
        current_period = {"start": month, "end": month, "user": user}
    else:
        if abs(month - current_period["end"]) <= 1\
          and current_period ["user"] == user:
            # period continues
            current_period ["end"] = month
        else: 
            # new period continues
            periods.append(current_period)
            current_period = {"start": month, "end": month, "user": user}
periods.append(current_period)


pprint (data)
pprint (periods)