sqlite-reader.py

#!/usr/bin/env python3.6

from datetime import datetime
import random
import sqlite3
import time


def main():
    prev_ts = time.time()
    time.sleep(0.600)

    conn = sqlite3.connect('example.db')

    while True:
        c = conn.cursor()
        c.execute("SELECT foo FROM data")
        rows = c.fetchall()
        assert(len(rows) == 1)
        curr_ts = rows[0][0]
        if not isinstance(curr_ts, float):
            print(f"{time.time()}: timestamp is not a float --> {curr_ts}")
        elif curr_ts == prev_ts:
            pass
        elif curr_ts < prev_ts:
            print(f"{time.time()}: timestamp moved backwards --> {prev_ts} to {curr_ts}")
        elif curr_ts > (prev_ts + 0.603):
            print(f"{time.time()}: timestamp moved forward too far --> {prev_ts} to {curr_ts}")
        else:
            print(f"{time.time()}: OK, timestamp advanced to {curr_ts}")
        prev_ts = curr_ts


if __name__ == "__main__":
    main()