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python - Dump data from JSON file to a class variable and access data from outside the class

I'm trying to store some data from a JSON file into a class variable that can be accessed by any other functions outside the class. The data in the JSON file will always be different, so I'm using a thread.

This is an example of my code.

class fruitStand(threading.Thread):
    
    fruitAmount = []
    
    def __init__(self):
        threading.Thread.__init__(self)
    
    def run(self):
        with open("fruitDatafile.json", "r") as fruitDatafile:
                fruitData = json.load(fruitDatafile)
        fruitValue = [
                fruitData["apples"], 
                fruitData["pears"], 
                fruitData["watermelons"], 
                fruitData["lemons"]]
        while True:
            self.fruitAmount.clear()
            for item in fruitValue:
                self.fruitAmount.append(item)
            time.sleep(3100)

fStand = fruitStand()
fStand.start()

print(fStand.fruitAmount)

The data seems to be stored correctly into the fruitAmount variable, but when I try to access it from outside the class, it shows as if there's nothing in it.


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1 Answer

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by (71.8m points)

print(fStand.fruitAmount) is being run before the thread is finished so it is empty. try printing it inside the run method or wait till the thread is complete using fStand.join() method


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