How to properly save temperature readings from thermal camera in CSV file, time vs. readings in one row - python-3.x

Question

This code is for MLX90640 infrared thermal camera. It plots a real-time temperature map across 768 (24x32) pixels using a Raspberry Pi that operates at roughly 1 frame per second. It also saves temperature data in CSV file. it wrights row per second where column A time (HH:MM:SS) then 768 readings from column "B" to column "ACN" but the problem is data in the first and last columns are mixed with double quotes and brackets e.g column "A" is 18:03:38 "[39.1 and column "ACN" is 36.8]" I used pop method and del method to delete " [ ] " but both shows out of index range. Any idea what cause this problem.
import RPi.GPIO as GPIO
import time,board,busio
import numpy as np
import adafruit_mlx90640
import matplotlib.pyplot as plt
from adafruit_blinka import Enum, Lockable, agnostic
import csv
import datetime
i2c = busio.I2C(board.SCL, board.SDA, frequency=800000) # setup I2C for thermal camera
thermal_mapfile = str(datetime.datetime.now().date()) + '_' + str(datetime.datetime.now().time()).replace(':', '.')
thermal_mapfile = thermal_mapfile[:16] #limit thermal file name to 16 characters
print("Thermal cam is ON")
mlx = adafruit_mlx90640.MLX90640(i2c) # begin MLX90640 with I2C comm
mlx.refresh_rate = adafruit_mlx90640.RefreshRate.REFRESH_2_HZ # set refresh rate 2Hz
mlx_shape = (24,32)
print("Initialized")
# setup the figure for plotting
plt.ion() # enables interactive plotting
fig,ax = plt.subplots(figsize=(12,7))
therm1 = ax.imshow(np.zeros(mlx_shape),vmin=0,vmax=60) #start plot with zeros
cbar = fig.colorbar(therm1) # setup colorbar for temps
cbar.set_label('Temperature [$^{\circ}$C]',fontsize=14) # colorbar label
t_array = []
frame = [0] * 768
t1 = time.monotonic()
while True:
try:
mlx.getFrame(frame) # read MLX temperatures into frame var
data_array = (np.reshape(frame,mlx_shape)) # reshape to 24x32
therm1.set_data(np.fliplr(data_array)) # flip left to right
therm1.set_clim(vmin=np.min(data_array),vmax=np.max(data_array)) # set bounds
cbar.update_normal(therm1) # update colorbar range
plt.title(f"Max Temp: {np.max(data_array):.1f}C")
plt.pause(0.001) # required
t_array.append(time.monotonic()-t1)
except ValueError:
continue # if error, just read again
for h in range(24):
for w in range(32):
t = frame[h*32 + w]
frame = list(np.around(np.array(frame),1)) #round array elements to one decimal point
with open("/home/pi/Thermal_Camera/"+thermal_mapfile+".csv","a") as thermalfile:
writer = csv.writer(thermalfile,delimiter=" ")
unix_time = time.time()
formatted_time = datetime.datetime.fromtimestamp(unix_time).strftime('%H:%M:%S')
writer.writerow([formatted_time,frame])

Answer 1

An example of what I am talking about:
import csv
import datetime
hdrs = ['dt','a', 'b', 'c']
data_list = [1, 2, 3]
#Case 1, passing a list directly.
with open('csv_list_test.csv', 'w') as csv_file:
csv_writer = csv.writer(csv_file, delimiter='|')
csv_writer.writerow(hdrs)
csv_writer.writerow([datetime.datetime.now().isoformat(), data_list])
cat csv_list_test.csv
dt|a|b|c
2023-01-24T17:17:44.961821|[1, 2, 3]
# Case 2, unpack list.
with open('csv_list_test.csv', 'w') as csv_file:
csv_writer = csv.writer(csv_file, delimiter='|')
csv_writer.writerow(hdrs)
csv_writer.writerow([datetime.datetime.now().isoformat(), *data_list])
cat csv_list_test.csv
dt|a|b|c
2023-01-24T17:18:32.337160|1|2|3
I use a delimiter that makes it easy to distinguish the columns. delimiter=" " is not a good idea.
In Case 1 you can see that the list is all in column a.
In Case 2 unpacking(*data_list) the list puts the individual elements in the appropriate columns.