ICON SDK for Python is a collection of libraries which allow you to interact with a local or remote Loopchain node, using an HTTP connection.
Project description
title: "ICON SDK for Python" excerpt: ""
ICON SDK for Python is a collection of libraries which allows you to interact with a local or remote ICON node using an HTTP connection. The following documentation will guide you through installing and running ICON SDK for Python, and provide API reference documentation examples. It is reference to ICON JSON-RPC API v3.
Table of Contents
- Quick Start
- Queries
- Loading a Wallet and Storing the Keystore
- API Methods of KeyWallet
- Transactions
- Estimating step
Quick Start
Requirements
ICON SDK for Python development and execution requires the following environments.
- Python
- Version: Python 3.6+
- IDE: Pycharm is recommended.
Reference
Version
1.2.0
Installation
First, you need to get ICON SDK for Python into your project. It can be installed using pip as follows:
$ pip install iconsdk
Creating an IconService Instance and Setting a Provider
Next, you need to create an IconService instance and set a provider.
-
The IconService class contains a set of API methods. It accepts a HTTPProvider which serves the purpose of connecting to HTTP and HTTPS based JSON-RPC servers.
-
A provider defines how the IconService connects to ICON node.
-
The HTTPProvider takes a base domain URL where the server can be found. For local development, this would be something like
http://localhost:9000.
Here is an example of calling a simple API method to get a block by its height:
from iconsdk.icon_service import IconService
from iconsdk.providers.http_provider import HTTPProvider
# Creates an IconService instance using the HTTP provider and set a provider.
icon_service = IconService(HTTPProvider("http://localhost:9000", 3))
# Gets a block by a given block height.
block = icon_service.get_block(1209)
Using logger
Set a logger named ICON-SDK-PYTHON if necessary. Use set_logger function to set log level like "DEBUG", "INFO", etc as shown below.
from iconsdk.utils import set_logger
# Sets level in the logger. In this case, the handler is default StreamHandler which writes logging records, appropriately formatted, to a stream.
set_logger("DEBUG")
You can also set logger with a specific handler like FileHandler or SteamHandler and user own log format as shown below.
from logging import StreamHandler, Formatter
# Sets level in the logger. In this case, the handler is FileHandler which writes formatted logging records to disk files.
handler = FileHandler("./icon-sdk-python.log", mode='a', encoding=None, delay=False)
# Sets user own log format.
formatter = Formatter('%(asctime)s %(name)-12s %(levelname)-5s %(filename)-12s %(lineno)-4s %(funcName)-12s %(message)s')
set_logger("DEBUG", handler, formatter)
Queries
Examples
from iconsdk.builder.call_builder import CallBuilder
# Returns block information by block height
block = icon_service.get_block(1000)
# Returns block information by block hash
block = icon_service.get_block("0x000...000")
# Returns the last block information
block = icon_service.get_block("latest")
# Returns the balance of the account of given address
balance = icon_service.get_balance("hx000...1")
# Returns a list of the SCORE APIs
score_apis = icon_service.get_score_api("cx000...1")
# Returns the total supply of ICX
total_supply = icon_service.get_total_supply()
# Returns information about a transaction requested by transaction hash
tx = icon_service.get_transaction("0x000...000")
# Returns the result of a transaction by transaction hash
tx_result = icon_service.get_transaction_result("0x000...000")
# Generates a call instance using the CallBuilder
call = CallBuilder().from_(wallet.get_address())\
.to("cx000...1")\
.method("balance_of")\
.params({"address": "hx000...1"})\
.build()
# Executes a call method to call a read-only API method on the SCORE immediately without creating a transaction
result = icon_service.call(call)
Error Cases
There are different types of error cases as shown below. The exception is raised with the specific message. You can get more information about the exception from the message.
-
KeyStoreException
- It is raised when making or loading a key store file.
- Error code for the exception is 1.
-
AddressException
- It is raised when the address is invalid.
- Error code for the exception is 2.
-
BalanceException
- It is raised when the balance is invalid.
- Error code for the exception is 3.
-
DataTypeException
- It is raised when the data type is invalid.
- Error code for the exception is 4.
-
JSONRPCException
- It is raised when JSON-RPC response is an error.
- Error code for the exception is 5.
-
ZipException
- It is raised while writing zip in memory.
- Error code for the exception is 6.
get_block
get_block(value)
-
Function A
- Returns block information by block height
- Delegates to icx_getBlockByHeight RPC method
-
Function B
- Returns block information by block hash
- Delegates to icx_getBlockByHash RPC method
-
Function C
- Returns the last block information
- Delegates to icx_getLastBlock RPC method
Parameters
- Function A
- value : Integer of a block height
- Function B
- value : Hash of a block prefixed with '0x'
- Function C
- value : 'latest'
Returns
Block data
Example of a returned block data
Error Cases
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Returns block information by block height
block = icon_service.get_block(1000)
# Returns block information by block hash
block = icon_service.get_block("0x000...000")
# Returns the last block information
block = icon_service.get_block("latest")
get_balance
get_balance(address: str)
Returns the ICX balance of the given EOA or SCORE
Delegates to icx_getBalance RPC method
Parameters
address : An address of EOA or SCORE
Returns
Number of ICX coins
Error Cases
- AddressException : Address is invalid.
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Returns the ICX balance of the given EOA or SCORE
balance = icon_service.get_balance("hx000...1")
get_score_api
get_score_api(address: str)
Returns SCORE's external API list
Delegates to icx_getScoreApi RPC method
Parameters
address : A SCORE address to be examined
Returns
A list of API methods of the SCORE and its information
Fields :
- type : Method type; function, fallback, or eventlog
- name : Function name on the SCORE
- inputs : A list of information of parameters
- name : Parameter name
- type : Parameter type ; int, str, bytes, bool, Address
- indexed : In the case of eventlog, tells if the parameter is indexed.
- outputs : Return value
- type : Return value type ; int, str, bytes, bool, Address
- Readonly : External (readonly=True)
- Payable: Payable
Error Cases
- AddressException : Address is invalid.
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Returns SCORE's external API list
score_apis = icon_service.get_score_api("cx000...1")
get_total_supply
get_total_supply()
Returns total ICX coin supply that has been issued
Delegates to icx_getTotalSupply RPC method
Parameters
None
Returns
Total number of ICX coins issued
Error Cases
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Returns total ICX coin supply that has been issued
total_supply = icon_service.get_total_supply()
get_transaction
get_transaction(tx_hash: str)
Returns the transaction information requested by transaction hash
Delegates to icx_getTransactionByHash RPC method
Parameters
tx_hash : Transaction hash prefixed with '0x'
Returns
Information about a transaction
Fields :
- version : Protocol version (3 for V3)
- from : An EOA address that created the transaction
- to : An EOA address to receive coins, or SCORE address to execute the transaction
- value : Amount of ICX coins in loop to transfer. When omitted, assumes 0. (1 icx = 10 ^ 18 loop)
- stepLimit : Maximum step allowance that can be used by the transaction
- timestamp : Transaction creation time. Timestamp is in microseconds.
- nid : Network ID (1 for Main net, etc)
- nonce : An arbitrary number used to prevent transaction hash collision
- txHash : Transaction hash
- txIndex : Transaction index in a block. Null when it is pending.
- blockHeight : Block height including the transaction. Null when it is pending
- blockHash : Block hash including the transaction. Null when it is pending.
- signature : Signature of the transaction
- dataType : Data type; call, deploy, message
- data : Contains various type of data depending on the dataType
Error Cases
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Returns the transaction information requested by transaction hash
tx = icon_service.get_transaction("0x000...000")
get_transaction_result
get_transaction_result(tx_hash: str)
Returns the transaction result requested by transaction hash
Delegates to icx_getTransactionResult RPC method
Parameters
tx_hash : Hash of a transaction prefixed with '0x'
Returns
A transaction result object
Field :
- status : 1 on success, 0 on failure
- to : Recipient address of the transaction
- failure : This field exists when status is 0. Contains code(str) and message(str)
- txHash : Transaction hash
- txIndex : Transaction index in the block
- blockHeight : Block height including the transaction
- blockHash : Block hash including the transaction
- cumulativeStepUsed : Sum of stepUsed by this transaction and all preceding transactions in the same block
- stepUsed : The amount of step used by this transaction
- stepPrice: The step price used by this transaction
- scoreAddress : A SCORE address if the transaction created a new SCORE. (optional)
- eventLogs : Array of eventlogs generated by this transaction
- logsBloom : Bloom filter to quickly retrieve related eventlogs
Error Cases
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Returns the transaction result requested by transaction hash
tx_result = icon_service.get_transaction_result("0x000...000")
call
call(call: Call)
Calls SCORE's external function which is read-only without creating a transaction.
Delegates to icx_call RPC method
Parameters
Call object made by CallBuilder
Fields :
- from : Message sender's address (optional)
- to : A SCORE address that will handle the message
- method : name of an external function
- params : Parameters to be passed to the function (optional). A data type of params should be dict.
Returns
Values returned by the executed SCORE function
Error Cases
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Generates a call instance using the CallBuilder
call = CallBuilder().from_(wallet.get_address())\
.to("cx000...1")\
.method("balance_of")\
.params({"address": "hx000...1"})\
.build()
# Calls SCORE's external function which is read-only without creating a transaction
result = icon_service.call(call)
Loading a Wallet and Storing the Keystore
To send transactions, first, you should make an instance of your wallet.
You can make an instance of the wallet using bytes of the private key or from a keystore file.
Examples
from iconsdk.wallet.wallet import KeyWallet
# Generates a wallet
wallet = KeyWallet.create()
# Loads a wallet from bytes of the private key
wallet = KeyWallet.load(b'-B\x99...xedy')
# Loads a wallet from a keystore file
wallet = KeyWallet.load("./keystore", "password")
# Stores a keystore file on the file path
wallet.store("./keystore", "password") # throw exception if having an error.
# Returns an Address
wallet.get_address()
# Returns a private key
wallet.get_private_key()
# Signs the transaction
signature = wallet.sign(b'D8\xe9...\xfc')
API Methods of KeyWallet
create
create()
Generates an instance of Wallet without a specific private key
Parameters
None
Returns
An instance of Wallet class
Example
# Generates a wallet
wallet = KeyWallet.create()
load
load(private_key: bytes)
Loads a wallet from bytes of the private key and generates an instance of Wallet
Parameters
private_key : Bytes of the private key
Returns
An instance of Wallet class
Error Cases
- DataTypeException : Private key is invalid.
Example
# Loads a wallet from bytes of the private key
wallet = KeyWallet.load(b'-B\x99...xedy')
load
load(file_path, password)
Loads a wallet from a keystore file with your password and generates an instance of Wallet
Parameters
-
file_path : File path of the keystore file
-
password : Password for the keystore file. Password must include alphabet character, number, and special character
Returns
An instance of Wallet class
Error Cases
- KeyStoreException: Key store file is invalid.
Example
# Loads a wallet from a keystore file
wallet = KeyWallet.load("./keystore", "password")
store
store(file_path, password)
Stores data of an instance of a derived wallet class on the file path with your password
Parameters
-
file_path : File path of the keystore file
-
password : Password for the keystore file. Password must include alphabet character, number, and special character
Returns
None
Error Cases
- KeyStoreException: Key store file is invalid.
Example
# Stores a keystore file on the file path
wallet.store("./keystore", "password") # throw exception if having an error.
get_address
get_address()
Returns an EOA address
The format of your account (which is generated from your public key) is hxfd7e4560ba363f5aabd32caac7317feeee70ea57.
Parameters
None
Returns
An EOA address
Example
# Returns an EOA address
wallet.get_address()
get_private_key
get_private_key()
Returns hex string of the private key of the wallet
Parameters
None
Returns
Hex string of the private key
Example
# Returns the private key
wallet.get_private_key()
sign
sign(data: bytes)
Returns bytes of the ECDSA-SHA256 signature made from the data
Parameters
data : bytes of the transaction
Returns
Bytes of the signature
Error Cases
- DataTypeException : Data type is invalid.
Example
# Signs the transaction
signature = wallet.sign(b'D8\xe9...\xfc')
Transactions
Generating a Transaction
Next, you should create an instance of the transaction using different types of transaction builders as follows:
Signing a Transaction
Before sending a transaction, the transaction should be signed by using SignedTransaction class. The SignedTransaction class is used to sign the transaction by returning an instance of the signed transaction as demonstrated in the example below. The instance of the signed transaction has the property of a signature.
Sending a Transaction
Finally, you can send a transaction with the signed transaction object as follows:
Examples
from iconsdk.builder.transaction_builder import (
TransactionBuilder,
DeployTransactionBuilder,
CallTransactionBuilder,
MessageTransactionBuilder,
DepositTransactionBuilder
)
from iconsdk.signed_transaction import SignedTransaction
# Generates an instance of transaction for sending icx.
transaction = TransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.value(150000000)\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.build()
# Generates an instance of transaction for deploying SCORE.
transaction = DeployTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.content_type("application/zip")\
.content(b'D8\xe9...\xfc')\
.params(params)\
.build()
# Generates an instance of transaction for calling method in SCORE.
transaction = CallTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.method("transfer")\
.params(params)\
.build()
# Generates an instance of transaction for sending a message.
transaction = MessageTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.data("0x74657374")\
.build()
# Generates an instance of transaction for adding or withdrawing a deposit.
# Case0: Adding a deposit
transaction = DepositTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.value(5000*(10**18))\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.action("add") \
.build()
# Case1: Withdrawing the deposit
transaction = DepositTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.action("withdraw") \
.id(tx_hash) \
.build()
# Returns the signed transaction object having a signature
signed_transaction = SignedTransaction(transaction, wallet)
# Sends the transaction
tx_hash = icon_service.send_transaction(signed_transaction)
TransactionBuilder
Builder for a Transaction object
Methods
- from_ : The wallet address making a transaction. The default address is your account address.
- to : The wallet address to receive coin or SCORE address to receive a transaction.
- value : The amount of ICX to be sent. (Optional)
- step_limit : The maximum step value for processing a transaction.
- nid : Network ID. Default nid is 1 if you didn't set the value. (1 for Main net, etc)
- nonce : An arbitrary number used to prevent transaction hash collision. (Optional)
- version : Protocol version (3 for V3). The default version is 3 if you didn't set the value.
- timestamp : Transaction creation time. Timestamp is in microseconds. Default timestamp is set, if you didn't set the value.
- build : Returns an ICX transaction object
Returns
A transaction object
Example
# Generates an instance of transaction for sending icx.
transaction = TransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.value(150000000)\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.build()
DeployTransactionBuilder
Builder for DeployTransaction object
Methods
- from_ : The wallet address making a transaction. The default address is your account address.
- to : The wallet address to receive coin or SCORE address to receive a transaction
- step_limit : The maximum step value for processing a transaction
- nid : Network ID. Default nid is 1 if you didn't set the value. (1 for Main net, etc)
- nonce : An arbitrary number used to prevent transaction hash collision
- content_type : Content's MIME type
- content : Binary data of the SCORE
- params : Parameters passed on the SCORE methods ; on_install (), on_update (). Data type of the params should be dict. (optional)
- version : Protocol version (3 for V3). The default version is 3 if you didn't set the value.
- timestamp : Transaction creation time. Timestamp is in microseconds. Default timestamp is set, if you didn't set the value.
- build : Returns a deploy transaction object
Returns
A deploy transaction object
Example
# Generates an instance of transaction for deploying SCORE.
transaction = DeployTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.content_type("application/zip")\
.content(b'D8\xe9...\xfc')\
.params(params)\
.build()
CallTransactionBuilder
Builder for CallTransaction object
Methods
- from_ : The wallet address making a transaction. The default address is your account address.
- to : The wallet address to receive coin or SCORE address to receive a transaction
- step_limit : The maximum step value for processing a transaction
- nid : Network ID. Default nid is 1 if you didn't set the value. (1 for Main net, etc)
- nonce : An arbitrary number used to prevent transaction hash collision
- method : Methods in the SCORE
- params : Parameters passed on the SCORE methods. Data type of the params should be dict. (optional)
- version : Protocol version (3 for V3). The default version is 3 if you didn't set the value.
- timestamp : Transaction creation time. Timestamp is in microseconds. Default timestamp is set, if you didn't set the value.
- Build : Returns a call transaction object
Returns
A call transaction object
Example
# Generates an instance of transaction for calling method in SCORE.
transaction = CallTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.method("transfer")\
.params(params)\
.build()
MessageTransactionBuilder
Builder for MessageTransaction object
Methods
- from_ : The wallet address making a transaction. The default address is your account address.
- to : The wallet address to receive coin or SCORE address to receive a transaction
- stepLimit : The maximum step value for processing a transaction
- nid : Network ID. Default nid is 1 if you didn't set the value. (1 for Main net, etc)
- nonce : An arbitrary number used to prevent transaction hash collision
- data : Data by the dataType. Data type of the data should be lowercase hex string prefixed with '0x'.
- version : Protocol version (3 for V3). The default version is 3 if you didn't set the value.
- timestamp : Transaction creation time. Timestamp is in microseconds. Default timestamp is set, if you didn't set the value.
- build : Returns a message transaction object
Returns
A message transaction object
Example
# Generates an instance of transaction for sending a message.
transaction = MessageTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.data("0x74657374")\
.build()
DepositTransactionBuilder
Builder for DepositTransaction object
Methods
- from_ : The wallet address making a transaction. The default address is your account address.
- to : SCORE address to receive a transaction
- value : The amount of ICX to be deposited. It is used only for 'add' action. (Optional)
- action : "add" or "withdraw".
- id : Transaction hash prefixed with '0x'. It is used only for 'withdraw' action. (Optional)
- stepLimit : The maximum step value for processing a transaction.
- nid : Network ID. Default nid is 1 if you didn't set the value. (1 for Main net, etc)
- nonce : An arbitrary number used to prevent transaction hash collision.
- version : Protocol version (3 for V3). The default version is 3 if you didn't set the value.
- timestamp : Transaction creation time. Timestamp is in microseconds. Default timestamp is set, if you didn't set the value.
- build : Returns a deposit transaction object.
Returns
A deposit transaction object
Example
# Generates an instance of transaction for adding or withdrawing a deposit.
# Case0: Adding a deposit
transaction = DepositTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.value(5000*(10**18))\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.action("add") \
.build()
# Case1: Withdrawing the deposit
transaction = DepositTransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.step_limit(1000000)\
.nid(3)\
.nonce(100)\
.action("withdraw") \
.id(tx_hash) \
.build()
SignedTransaction
SignedTransaction(transaction: Transaction, wallet: Wallet)
Returns the signed transaction object having a signature
Parameters
- transaction : A transaction object not having a signature field yet
- wallet : A wallet object
Returns
The signed transaction object having a signature field finally
Error Cases
- DataTypeException : Data type is invalid.
Example
# Returns the signed transaction object having a signature
signed_transaction = SignedTransaction(transaction, wallet)
send_transaction
send_transaction(signed_transaction: SignedTransaction)
Sends the transaction
Delegates to icx_sendTransaction RPC method
Need to wait for a while after sending the transaction. Because it takes time to create consensus among nodes. We recommend 0.3 seconds at least.
Parameters
signed_transaction : A signed transaction object
Returns
Transaction hash prefixed with '0x'
Error Cases
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Sends the transaction
tx_hash = icon_service.send_transaction(signed_transaction)
Estimating Step
It is important to set a proper step_limit value in your transaction to make the submitted transaction executed successfully.
estimate_step API provides a way to estimate the Step usage of a given transaction. Using the method, you can get an estimated Step usage before sending your transaction then make a SignedTransaction with the step_limit based on the estimate.
Examples
# Generates a raw transaction without the stepLimit
transaction = TransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.value(150000000)\
.nid(3)\
.nonce(100)\
.build()
# Returns an estimated step value
estimate_step = icon_service.estimate_step(transaction)
# Adds some margin to the estimated step
estimate_step += 10000
# Returns the signed transaction object having a signature with the same raw transaction and the estimated step
signed_transaction = SignedTransaction(transaction, wallet, estimate_step)
# Sends the transaction
tx_hash = icon_service.send_transaction(signed_transaction)
Note that the estimate can be smaller or larger than the actual amount of step to be used by the transaction, so it is recommended to add some margin to the estimate when you set the step_limit of the SignedTransaction.
estimate_step
estimate_step(transaction: Transaction)
Returns an estimated step of how much step is necessary to allow the transaction to complete
Delegates to debug_estimateStep RPC method
Parameters
transaction : An Transaction object made by TransactionBuilder
Returns
Number of an estimated step
Error Cases
- DataTypeException : Data type is invalid.
- JSONRPCException : JSON-RPC Response is error.
Example
# Generates a raw transaction without the stepLimit
transaction = TransactionBuilder()\
.from_(wallet.get_address())\
.to("cx00...02")\
.value(150000000)\
.nid(3)\
.nonce(100)\
.build()
# Returns an estimated step value
estimate_step = icon_service.estimate_step(transaction)
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