https://github.com/polkascan/py-substrate-interface

Python Substrate Interface
https://github.com/polkascan/py-substrate-interface

blockchain client interface polkadot polkascan python substrate

Last synced: about 1 month ago
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Python Substrate Interface

• Host: GitHub
• URL: https://github.com/polkascan/py-substrate-interface
• Owner: polkascan
• License: apache-2.0
• Created: 2019-04-12T11:52:31.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2024-04-11T14:11:49.000Z (8 months ago)
• Last Synced: 2024-04-11T18:44:06.063Z (8 months ago)
• Topics: blockchain, client, interface, polkadot, polkascan, python, substrate
• Language: Python
• Homepage: https://polkascan.github.io/py-substrate-interface/
• Size: 4.26 MB
• Stars: 232
• Watchers: 21
• Forks: 106
• Open Issues: 29
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Python Substrate Interface

[![Build Status](https://img.shields.io/github/actions/workflow/status/polkascan/py-substrate-interface/unittests.yml?branch=master)](https://github.com/polkascan/py-substrate-interface/actions?query=workflow%3A%22Run+unit+tests%22)

[![Latest Version](https://img.shields.io/pypi/v/substrate-interface.svg)](https://pypi.org/project/substrate-interface/)

[![Supported Python versions](https://img.shields.io/pypi/pyversions/substrate-interface.svg)](https://pypi.org/project/substrate-interface/)

[![License](https://img.shields.io/pypi/l/substrate-interface.svg)](https://github.com/polkascan/py-substrate-interface/blob/master/LICENSE)

## Description

This library specializes in interfacing with a [Substrate](https://substrate.io/) node; querying storage, composing extrinsics, 

SCALE encoding/decoding and providing additional convenience methods to deal with the features and metadata of 

the Substrate runtime.

## Documentation

* [Library documentation](https://polkascan.github.io/py-substrate-interface/)

* [Metadata documentation for Polkadot and Kusama ecosystem runtimes](https://polkascan.github.io/py-substrate-metadata-docs/)

## Installation

```bash

pip install substrate-interface

```

## Initialization

```python

substrate = SubstrateInterface(url="ws://127.0.0.1:9944")

```

After connecting certain properties like `ss58_format` will be determined automatically by querying the RPC node. At 

the moment this will work for most `MetadataV14` and above runtimes like Polkadot, Kusama, Acala, Moonbeam. For 

older or runtimes under development the `ss58_format` (default 42) and other properties should be set manually. 

## Quick usage

### Balance information of an account

```python

result = substrate.query('System', 'Account', ['F4xQKRUagnSGjFqafyhajLs94e7Vvzvr8ebwYJceKpr8R7T'])

print(result.value['data']['free']) # 635278638077956496

```

### Create balance transfer extrinsic

```python

call = substrate.compose_call(

    call_module='Balances',

    call_function='transfer',

    call_params={

        'dest': '5E9oDs9PjpsBbxXxRE9uMaZZhnBAV38n2ouLB28oecBDdeQo',

        'value': 1 * 10**12

    }

)

keypair = Keypair.create_from_uri('//Alice')

extrinsic = substrate.create_signed_extrinsic(call=call, keypair=keypair)

receipt = substrate.submit_extrinsic(extrinsic, wait_for_inclusion=True)

print(f"Extrinsic '{receipt.extrinsic_hash}' sent and included in block '{receipt.block_hash}'")

```

## Contact and Support 

For questions, please see the [Substrate StackExchange](https://substrate.stackexchange.com/questions/tagged/python), [Github Discussions](https://github.com/polkascan/py-substrate-interface/discussions) or 

reach out to us on our [matrix](http://matrix.org) chat group: [Polkascan Technical](https://matrix.to/#/#polkascan:matrix.org).

## License

https://github.com/polkascan/py-substrate-interface/blob/master/LICENSE