hashlib在python中编写区块链

我正在尝试创建一个区块链。运行时，我收到以下错误：

"  File "<ipython-input-3-7d6dab8d7cb5>", line 50
    content_hash= hashlib.sha256(content).hexdigest()
               ^
SyntaxError: invalid syntax"

---

错误实际上是前几行的结果。它们没有正确关闭（您忘记了结束括号“}”）…因此解释器试图将下一行包含在它们中，并且不知道如何执行

更正：

def valid_proof(self, index, hash_of_previous_block, transactions, nonce):
    #create a string containing the hash of the previous block and the block content, including the nonce 
    content ={
              f'{index}{hash_of_previous_block}{transactions}{nonce}'.encode()
              }
    #hash using sha256
    content_hash = hashlib.sha256(content).hexdigest()

---

您从未关闭过花括号

content={

，直到

返回后，您才可以这样做
def valid_proof(self, index, hash_of_previous_block, transactions, nonce):
    #create a string containing the hash of the previous block and the block content, including the nonce 
    content ={
              f'{index}{hash_of_previous_block}{transactions}{nonce}'.encode()
              }
    #hash using sha256
    content_hash = hashlib.sha256(content).hexdigest()