- Foundations of Blockchain
- Koshik Raj
- 204字
- 2021-07-02 14:17:17
Block structure
Let's consider a simple block whose header and data are combined to create a data structure called Block. Each Block will contain the following: an index, the previous hash, a timestamp, data, and its own hash value:
class Block(object): """A class representing the block for the blockchain""" def __init__(self, index, previous_hash, timestamp, data, hash): self.index = index self.previous_hash = previous_hash self.timestamp = timestamp self.data = data self.hash = hash
The preceding code snippet defines a Python class called Block that has all the basic attributes of a blockchain block. Usually, a block will contain both a header and a body, with the header containing metadata about the block. However, the preceding example doesn't distinguish between the header and the body. A typical blockchain application, such as Bitcoin, will have a huge set of data that could be in the form of transactions, but in the example, we will consider the data to be of a string type.
A typical block will also contain a nonce and a difficulty target in the header. This information is used in consensus algorithms, such as Proof of Work. Since our intention is just to describe a blockchain, these fields are outside the scope of this section.