I'm having a problem about the topic in the title. I created a python script on the directory /home/pi/ and it starts running on the background when the Raspberry Pi is booted. It's duty is this:
When I push a button that is connected to one of the GPIO's, it will create a folder in it's own directory, then create a text file called 'fileName.txt' at the directory /home/pi/; and write the name of the folder it just created, in this text file. Everything goes fine until the 'create a text file' part. I boot the Raspberry Pi, then I push the button. The script creates the folder that I want, but after that, it doesn't create the text file. Since it runs in background, I can't see the error on the terminal that may explain the problem. After that, I tried starting the script manually to see the error message; however, this time it worked perfectly well. It created the text file and wrote the name of the folder in it.
This is the simple code that I use to create the file:
text_file = open("folderName.txt", "w")
text_file.write("%s" %folderName)
text_file.close()
Anyone knows how to solve it?
It is probably creating the file in the wrong folder. Try specifying the absolute path where you want to create the file, or discover it inside the script, like the example below:
import os
cwd = os.path.dirname(os.path.abspath(__file__))
text_file = open(os.path.join(cwd, "folderName", "textFile.txt"), "w")
Also, to test a script that is running in background, you can write debug messages to a log file in /var/log (might need root permission) or /tmp, either using the Logging module with a FileHandler, or using the open built-in function.