import os
import csv

def sec_to_min(sec):
    """converts seconds to MM:SS"""
    mins = int(sec / 60)
    sec_left = sec % 60
    return str(mins).zfill(2) + ":" + str(sec_left).zfill(2)

def sess_to_log(session, filename):
    """writes session dict to logfile specified"""
    fields = []
    for field in session.keys():
        fields.append(field)

    if os.path.exists(filename):
        logmode = 'a'
    else:
        logmode = 'w'
    with open(filename, logmode) as logfile:
        writer = csv.DictWriter(logfile, fieldnames=fields)
        if logmode == 'w':
            writer.writeheader()
        writer.writerow(session)