neo

class NEO

Bases: object

A class used to represent the NEO native contract.

Check out Neo’s Documentation to learn more about the NEO class.

hash: UInt160

classmethod symbol() → str

Gets the symbol of NEO.

>>> NEO.symbol()
'NEO'

Returns:

the NEO string.

Return type:

str

classmethod decimals() → int

Gets the amount of decimals used by NEO.

>>> NEO.decimals()
0

Returns:

the number 0.

Return type:

int

classmethod totalSupply() → int

Gets the total token supply deployed in the system.

>>> NEO.totalSupply()
100000000

Returns:

the total token supply deployed in the system.

Return type:

int

classmethod balanceOf(account: UInt160) → int

Get the current balance of an address.

>>> NEO.balanceOf(UInt160(bytes(20)))
0

>>> NEO.balanceOf(UInt160(b'\xabv\xe2\xcb\xb0\x16,vG\x2f\x44Va\x10\x14\x19\xf3\xff\xa1\xe6'))
100

Parameters:

account (UInt160) – the account’s address to retrieve the balance for

Returns:

the account’s balance

Return type:

int

classmethod transfer(from_address: UInt160, to_address: UInt160, amount: int, data: Optional[Any] = None) → bool

Transfers an amount of GAS from one account to another.

If the method succeeds, it will fire the Transfer event and must return true, even if the amount is 0, or from and to are the same address.

>>> NEO.transfer(UInt160(b'\xc9F\x17\xba!\x99\x07\xc1\xc5\xd6   #\xe1\x9096\x89U\xac\x13'),     # this script hash needs to have signed the transaction or block
...              UInt160(b'\xabv\xe2\xcb\xb0\x16,vG\x2f\x44Va\x10\x14\x19\xf3\xff\xa1\xe6'),
...              10, None)
True

>>> NEO.transfer(UInt160(bytes(20)),
...              UInt160(b'\xabv\xe2\xcb\xb0\x16,vG\x2f\x44Va\x10\x14\x19\xf3\xff\xa1\xe6'),
...              10, None)
False

>>> NEO.transfer(UInt160(b'\xc9F\x17\xba!\x99\x07\xc1\xc5\xd6   #\xe1\x9096\x89U\xac\x13'),
...              UInt160(b'\xabv\xe2\xcb\xb0\x16,vG\x2f\x44Va\x10\x14\x19\xf3\xff\xa1\xe6'),
...              -1, None)
False

Parameters:

• from_address (UInt160) – the address to transfer from

• to_address (UInt160) – the address to transfer to

• amount (int) – the amount of NEO to transfer

• data (Any) – whatever data is pertinent to the onNEP17Payment method

Returns:

whether the transfer was successful

Return type:

bool

Raises:

Exception – raised if from_address or to_address length is not 20 or if amount is less than zero.

classmethod get_gas_per_block() → int

Gets the amount of GAS generated in each block.

>>> NEO.get_gas_per_block()
500000000

Returns:

the amount of GAS generated

Return type:

int

classmethod unclaimed_gas(account: UInt160, end: int) → int

Gets the amount of unclaimed GAS in the specified account.

>>> NEO.unclaimed_gas(UInt160(b'\xc9F\x17\xba!\x99\x07\xc1\xc5\xd6      #\xe1\x9096\x89U\xac\x13'), 0)
100000000

>>> NEO.unclaimed_gas(UInt160(bytes(20), 0)
100000000

Parameters:

• account (UInt160) – the account to check

• end (int) – the block index used when calculating GAS

classmethod register_candidate(pubkey: ECPoint) → bool

Registers as a candidate.

>>> NEO.register_candidate(ECPoint(b'\x03\x5a\x92\x8f\x20\x16\x39\x20\x4e\x06\xb4\x36\x8b\x1a\x93\x36\x54\x62\xa8\xeb\xbf\xf0\xb8\x81\x81\x51\xb7\x4f\xaa\xb3\xa2\xb6\x1a'))
False

Parameters:

pubkey (ECPoint) – The public key of the account to be registered

Returns:

whether the registration was a success or not

Return type:

bool

classmethod unregister_candidate(pubkey: ECPoint) → bool

Unregisters as a candidate.

>>> NEO.unregister_candidate(ECPoint(b'\x03\x5a\x92\x8f\x20\x16\x39\x20\x4e\x06\xb4\x36\x8b\x1a\x93\x36\x54\x62\xa8\xeb\xbf\xf0\xb8\x81\x81\x51\xb7\x4f\xaa\xb3\xa2\xb6\x1a'))
False

Parameters:

pubkey (ECPoint) – The public key of the account to be unregistered

Returns:

whether the unregistration was a success or not

Return type:

bool

classmethod vote(account: UInt160, vote_to: ECPoint) → bool

Votes for a candidate.

>>> NEO.vote(UInt160(b'\xc9F\x17\xba!\x99\x07\xc1\xc5\xd6       #\xe1\x9096\x89U\xac\x13'), ECPoint(b'\x03\x5a\x92\x8f\x20\x16\x39\x20\x4e\x06\xb4\x36\x8b\x1a\x93\x36\x54\x62\xa8\xeb\xbf\xf0\xb8\x81\x81\x51\xb7\x4f\xaa\xb3\xa2\xb6\x1a'))
False

Parameters:

• account (UInt160) – the account that is voting

• vote_to (ECPoint) – the public key of the one being voted

classmethod get_all_candidates() → Iterator

Gets the registered candidates iterator.

>>> NEO.get_all_candidates()
[]

Returns:

all registered candidates

Return type:

Iterator

classmethod un_vote(account: UInt160) → bool

Removes the vote of the candidate voted. It would be the same as calling vote(account, None).

>>> NEO.un_vote(UInt160(b'\xc9F\x17\xba!\x99\x07\xc1\xc5\xd6    #\xe1\x9096\x89U\xac\x13'))
False

Parameters:

account (UInt160) – the account that is removing the vote

classmethod get_candidates() → List[Tuple[ECPoint, int]]

Gets the list of all registered candidates.

>>> NEO.get_candidates()
[]

Returns:

all registered candidates

Return type:

List[Tuple[ECPoint, int]]

classmethod get_candidate_vote(pubkey: ECPoint) → int

Gets votes from specific candidate.

>>> NEO.get_candidate_vote(ECPoint(b'\x03\x5a\x92\x8f\x20\x16\x39\x20\x4e\x06\xb4\x36\x8b\x1a\x93\x36\x54\x62\xa8\xeb\xbf\xf0\xb8\x81\x81\x51\xb7\x4f\xaa\xb3\xa2\xb6\x1a'))
100

>>> NEO.get_candidate_vote(ECPoint(bytes(32)))
-1

Returns:

Votes or -1 if it was not found.

Return type:

int

classmethod get_committee() → List[ECPoint]

Gets all committee members list.

>>> NEO.get_committee()
[ b'\x02|\x84\xb0V\xc2j{$XG\x1em\xcfgR\xed\xd9k\x96\x88}x34\xe3Q\xdd\xfe\x13\xc4\xbc\xa2' ]

Returns:

all committee members

Return type:

List[ECPoint]

classmethod get_next_block_validators() → List[ECPoint]

Gets validators list of the next block.

>>> NEO.get_next_block_validators()
[ b'\x02|\x84\xb0V\xc2j{$XG\x1em\xcfgR\xed\xd9k\x96\x88}x34\xe3Q\xdd\xfe\x13\xc4\xbc\xa2' ]

Returns:

the public keys of the validators

Return type:

List[ECPoint]

classmethod get_account_state(account: UInt160) → NeoAccountState

Gets the latest votes of the specified account.

>>> NEO.get_account_state(UInt160(b'\xc9F\x17\xba!\x99\x07\xc1\xc5\xd6  #\xe1\x9096\x89U\xac\x13'))
{
    'balance': 100,
    'height': 2,
    'vote_to': None,
}

Parameters:

account (UInt160) – the specified account

Returns:

the state of the account

Return type:

NeoAccountState