get_daily_consecutive_meetings.py

import psycopg2
from itertools import groupby

conn_dtu = psycopg2.connect("<connstring>")
cur_dtu = conn_dtu.cursor()

cur_dtu.execute("select user_a, user_b, meeting_array from temp_friend_meetings where met_consecutive_days is null")

for idx, each in enumerate(cur_dtu.fetchall()):
    meeting_vector = each[2]
    grouped_L = [(k, sum(1 for i in g)) for k,g in groupby(meeting_vector)]
    sorted_group = sorted(grouped_L, key=lambda x: x[1], reverse=True)[0]
    cur_dtu.execute(""" UPDATE temp_friend_meetings SET met_consecutive_days=%s
                        WHERE user_a=%s AND user_b=%s""",
                    (int(sorted_group[1]),
                     each[0],
                     each[1],)
                    )
    
    print('user pair: ' + str(idx))
    if idx % 1000 == 0:
        print('saving..')
        conn_dtu.commit()
        print('saved')

conn_dtu.commit()