want to create a timestamp using GPS data with python3 - python-3.x

Question

python3 Newby here. I am trying to create a variable that I can use to make a GPS timestamp from an adafruit GPS sensor. I eventually want to store this in a db. The mysql database has a timestamp feature when data is inserted into a table so I want to have that and the UTC time and date that comes from the GPS device be stored as well.
It seems I have something wrong and can not figure it out. The code is hanging on this:
def gpstsRead():
gps_ts = '{}/{}/{} {:02}:{:02}:{:02}'.format(
gps.timestamp_utc.tm_mon,
gps.timestamp_utc.tm_mday,
gps.timestamp_utc.tm_year,
gps.timestamp_utc.tm_hour,
gps.timestamp_utc.tm_min,
gps.timestamp_utc.tm_sec,
)
return gps_ts
I am trying to put all of these into a timestamp like format. The error is this:
Traceback (most recent call last):
File "/home/pi/ek9/Sensors/GPS/gps-db-insert.py", line 57, in <module>
gps_ts = gpstsRead()
File "/home/pi/ek9/Sensors/GPS/gps-db-insert.py", line 20, in gpstsRead
gps.timestamp_utc.tm_mon,
AttributeError: 'NoneType' object has no attribute 'tm_mon'
I have made sure I use spaces instead of tabs as that has caused me grief in the past. Beyond that I really don't know. I have been putzing with this for hours to no avail. Any ideas? thanks for any suggestions.

Answer 1

Thanks all for the input. After reading these I decided to try it a little different. Instead of defining a variable with "def" i just decided to eliminate the "def" and just create the variable itself.
Like this:
# define values
gps_ts = ('{}-{}-{} {:02}:{:02}:{:02}'.format(
gps.timestamp_utc.tm_year,
gps.timestamp_utc.tm_mon,
gps.timestamp_utc.tm_mday,
gps.timestamp_utc.tm_hour,
gps.timestamp_utc.tm_min,
gps.timestamp_utc.tm_sec,)
)
And that seemed to work. For anyone that is doing something similar I will include the complete code. I also understand that like most languages, there is always more than one way to get the job done, some better than others, some not. I am still learning. If anyone cares to point out how I could accomplish the same task by doing something different or more efficient, please feel free to provide me the opportunity to learn. thanks again!
#!/usr/bin/python3
import pymysql
import time
import board
from busio import I2C
import adafruit_gps
i2c = I2C(board.SCL, board.SDA)
gps = adafruit_gps.GPS_GtopI2C(i2c) # Use I2C interface
gps.send_command(b"PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0")
gps.send_command(b"PMTK220,1000")
last_print = time.monotonic()
# Open database connection
db = pymysql.connect("localhost", "database", "password", "table")
# prepare a cursor object using cursor() method
cursor = db.cursor()
while True:
gps.update()
current = time.monotonic()
if current - last_print >= 1.0: # update rate
last_print = current
if not gps.has_fix:
# Try again if we don't have a fix yet.
print("Waiting for a satellite fix...")
continue
# define values
gps_ts = ('{}-{}-{} {:02}:{:02}:{:02}'.format(
gps.timestamp_utc.tm_year,
gps.timestamp_utc.tm_mon,
gps.timestamp_utc.tm_mday,
gps.timestamp_utc.tm_hour,
gps.timestamp_utc.tm_min,
gps.timestamp_utc.tm_sec,)
)
gps_lat = '{}'.format(gps.latitude)
gps_long = '{}'.format(gps.longitude)
gps_fix = '{}'.format(gps.fix_quality)
gps_sat = '{}'.format(gps.satellites)
gps_alt = '{}'.format(gps.altitude_m)
gps_speed = '{}'.format(gps.speed_knots)
gps_track = '{}'.format(gps.track_angle_deg)
sql = "INSERT into ek9_gps(gps_timestamp_utc, latitude, \
longitude, fix_quality, number_satellites, gps_altitude, \
gps_speed, gps_track_angle) \
values (%s,%s,%s,%s,%s,%s,%s,%s)"
arg = (gps_ts, gps_lat, gps_long, gps_fix, gps_sat,
gps_alt, gps_speed, gps_track)
try:
# Execute the SQL command
cursor.execute(sql, arg)
# Commit your changes in the database
db.commit()
except:
print('There was an error on input into the database')
# Rollback in case there is any error
db.rollback()
# disconnect from server
cursor.close()
db.close()
And this is what the mariadb shows:
+----+---------------------+---------------------+----------+-----------+-------------+-------------------+--------------+-----------+-----------------+
| id | datetime | gps_timestamp_utc | latitude | longitude | fix_quality | number_satellites | gps_altitude | gps_speed | gps_track_angle |
+----+---------------------+---------------------+----------+-----------+-------------+-------------------+--------------+-----------+-----------------+
| 11 | 2020-12-30 14:14:42 | 2020-12-30 20:14:42 | xx.xxxx | -xx.xxxx | 1 | 10 | 232 | 0 | 350 |
| 10 | 2020-12-30 14:14:41 | 2020-12-30 20:14:41 | xx.xxxx | -xx.xxxx | 1 | 10 | 232 | 0 | 350 |
| 9 | 2020-12-30 14:14:39 | 2020-12-30 20:14:39 | xx.xxxx | -xx.xxxx | 1 | 10 | 232 | 0 | 350 |
| 8 | 2020-12-30 14:14:38 | 2020-12-30 20:14:38 | xx.xxxx | -xx.xxxx | 1 | 10 | 232 | 0 | 350 |
Success!!! Thanks again!