How do I not overwrite my save data? (pickle in python)

Question

While using pickle, I came across a problem (for me) where it overwrites the save data with the default save data when the script is open up. Is there a way to detect if anything is in the file?

import pickle

savedata = ['tutorialisntfinished', 'tutorialisfinished', 'level1isntfinished', 'level1isfinished', 'level2isntfinished', 'level2isfinished', 'bossfightisntfinished', 'bossfightisfinished']
pickle.dump(savedata, open('savedata.json', 'wb'))    

And then I have some scripts that detect scenes and change variables.

I have a system to change save data by removing the (example)isntfinished from the list called savedata. All of this works, but When you reopen the script, it resets it. Anyone have a fix / solution for this?

Answer 1

Do this:

try:
    with open("fname", "xb") as fout:
        #Work with your open file
except FileExistsError:
    # Your error handling goes here

I can recommend you reading What does python3 open "x" mode do?