Tokens can represent virtually anything on the Electroneum Smart Chain:
reputation points in an online platform
skills of a character in a game
lottery tickets
financial assets like a share in a company
a fiat currency like USD
an ounce of gold
and more...
Such a powerful feature of the Electroneum Smart Chain must be handled by a robust standard, right? That's exactly where the ERC-20 plays its role! This standard allows developers to build token applications that are interoperable with other products and services.
What is ERC-20?
The ERC-20 introduces a standard for Fungible Tokens, in other words, they have a property that makes each Token be exactly the same (in type and value) as another Token. For example, an ERC-20 Token acts just like ETN, meaning that 1 Token is and will always be equal to all the other Tokens.
The ERC-20 (Ethereum Request for Comments 20), proposed by Fabian Vogelsteller in November 2015, is a Token Standard that implements an API for tokens within Smart Contracts.
Example functionalities ERC-20 provides:
transfer tokens from one account to another
get the current token balance of an account
get the total supply of the token available on the network
approve whether an amount of token from an account can be spent by a third-party account
If a Smart Contract implements the following methods and events it can be called an ERC-20 Token Contract and, once deployed, it will be responsible to keep track of the created tokens on Ethereum.
function name() public view returns (string)
function symbol() public view returns (string)
function decimals() public view returns (uint8)
function totalSupply() public view returns (uint256)
function balanceOf(address _owner) public view returns (uint256 balance)
function transfer(address _to, uint256 _value) public returns (bool success)
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success)
function approve(address _spender, uint256 _value) public returns (bool success)
function allowance(address _owner, address _spender) public view returns (uint256 remaining)
Let's see how a Standard is so important to make things simple for us to inspect any ERC-20 Token Contract on the Electroneum Smart Chain. We just need the Contract Application Binary Interface (ABI) to create an interface to any ERC-20 Token. As you can see below we will use a simplified ABI, to make it a low friction example.
Web3.py Example
First, make sure you have installed Web3.py↗ Python library:
