Is there a way to clear all data within a CSV file in order to fill it up again with new data?-CodePudding

I am trying to create an IOT weather station where in a Python file it would receive data from a temperature sensor and save it in a CSV along with the second(s) it was received.

Since this is going to be plotted in a graph in real time, I can't have it save new data without clearing the CSV file out first since if I did, the line in the graph will overlap, because of the eventual repetition of seconds in the CSV file.

This is a sample of what is saved in the CSV file:

Celcius,Time
56,20.50
57,20.50
58,20.50
59,20.50
00,20.50

I want the code to clear the CSV file once the seconds reach 60 (or 00), so it can be repopulated with new data.

This is what I have come up with so far:

with open('D:\\WORKSTUFF\\Coding\\ADET\\txt files\\testing.csv', 'a') as csv_file:
    csv_writer = csv.DictWriter(csv_file, fieldnames=fieldnames)
    info = {
        "Time": secondsNow[2],
        "Celcius": secondsNow[2]
    }
    if (secondsNow[2] == "00"):
        print("CLEAR CLEAR CLEAR")
        csv_file.close()
    else:
        csv_writer.writerow(info)

CodePudding user response：

When you open a csv file in python and write something into, it automatically overwrites what was already written in the file.

CodePudding user response：

You can clear the file by passing the shell command via python os module:

import os

...
print(CLEAR CLEAR CLEAR)
exit_code = os.system(": > $FILEPATH")
...