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I've recently been building a blockchain in Python. In my Block class, I initialise a nonce variable, which is then used later on in the class. However, when I try to use the variable elsewhere in the class, I get AttributeError: 'Block' object has no attribute 'nonce' . Here is my code:

from hashlib import sha256
class Block():
    def __init__(self, data=None):
        self.timestamp = str(time.time())
        self.data = data
        self.previousHash = '0'*64
        self.hash = self.calculateHash()
        self.nonce = 0
        self.dict = {
            "Previous hash": self.previousHash,
            "Hash": self.hash,
            "Timestamp": self.timestamp,
            "Data": self.data
    def mineBlock(self, difficulty):
        while self.hash[:difficulty] != '0'*difficulty:
            self.nonce += 1
            self.calculateHash()
        print('Block mined: ' + self.hash)
    def calculateHash(self):
        hashingText = f'{self.timestamp}{self.data}{self.previousHash}{self.nonce}'.encode(
            'utf-8')
        return sha256(hashingText).hexdigest()
Here is the last part of the error, in case it helps:
File "/Users/[MYNAME]/Developer/DigiGov/src/BlockClass.py", line 28, in calculateHash
    hashingText = f'{self.timestamp}{self.data}{self.previousHash}{self.nonce}'.encode(
AttributeError: 'Block' object has no attribute 'nonce'
        
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