How to convert ss58 address to a different parachain in py-substrate-interface

Question

I have code to convert ss58 address to a different parachain using polkadot{js}, such as below:

const { Keyring } = require("@polkadot/keyring");
const keyring = new Keyring();
keyring.encodeAddress("5EChUec3ZQhUvY1g52ZbfBVkqjUY9Kcr6mcEvQMbmd38shQL", 10);

What would be the equivalent is python using the py-substrate-interface?

Answer 1

py-substrate-interface provides helper functions for that in the utils.ss58 namespace.
Transforming an address from one chain-id to another can look like this:

from substrateinterface.utils.ss58 import ss58_decode, ss58_encode

addr = "5EChUec3ZQhUvY1g52ZbfBVkqjUY9Kcr6mcEvQMbmd38shQL"
# This is optional, but good for input validation.
input_id = 42
output_id = 10

pk = ss58_decode(addr, valid_ss58_format=input_id)
output = ss58_encode(pk, ss58_format=output_id)

print("Input  addr (network={}): {}".format(input_id, addr))
print("Output addr (network={}): {}".format(output_id, output))

prints:

Input  addr (network=42): 5EChUec3ZQhUvY1g52ZbfBVkqjUY9Kcr6mcEvQMbmd38shQL
Output addr (network=10): 231bCuH9G6iDvf4q5zQqaLzAACu8PTUC4ft3EXmxxG1Xs6HW

You can verify the results on polkadot-js https://polkadot.js.org/apps/#/utilities