Churn in Bitdeli

gistfile1.py

import bitdeli, json
from datetime import datetime
from time import mktime, strptime

bitdeli.set_theme('eighties')

BASELINE = mktime(strptime('2012-03-01', '%Y-%m-%d'))
all_users = [0] * 30
active_users = [0] * 30

def time(t):
    return datetime.utcfromtimestamp(t)

def activity(events, zeroday):
    prev_day = 0
    yield 0
    for event in events:
        t = event['properties']['time']
        # Nth day of activity since signup
        day = (time(t) - zeroday).days
        if day > 0 and day != prev_day:
            prev_day = day
            if day < 30:
                yield day

def chart(data, label, color):
    # normalize counts to % of all users
    norm = lambda x: round((100 * x / float(data[0])), 1)
    bitdeli.Bar(label=label,
                size=[12,2],
                color=color,
                data=list(enumerate(map(norm, data)))[1:])

for profile in bitdeli.profiles():
    events = [json.loads(e) for e in profile['events']]
    if events[0]['event'] == '$signup':
        signup_time = events[0]['properties']['time']
        if signup_time > BASELINE:
            # loop over all events
            for day in activity(events[1:], time(signup_time)):
                # count the number of users active on the Nth day after signup
                all_users[day] += 1

chart(all_users, 'Days since signup - % all users', color=1)