How to assign a variable based on the output of a function

Question

I cannot figure out how to assign a variable based on the output of a function. I basically want to do this in my __init__ method

def square(x):
    y = x * x
    return y

toSquare = 10
result = square(toSquare)

My init method looks like this

def __init__(self):
        self.init(
            hash = sp.bytes('0x'),
            nat_value = self.somefunction(),   <-this does not work

        )

Answer 1

Smart contracts are codeless during origination. By this, I mean that you don't run any smart-contract code during origination.

Above, you are leveraging meta-programming to build the initial storage of the contract, and you cannot use any entry point function there.

Example of what you can do:

import smartpy as sp

class MyContract(sp.Contract):
    def __init__(self):
        self.init(b = self.a())

    def a(self):         
        b = 1
        return b

    @sp.entry_point        <- Only executable at runtime
    def ep(self):
        pass

@sp.add_test(name = "Sample")
def test():
   scenario = sp.test_scenario()
   c1 = MyContract()
   scenario += c1
   c1.ep()