sp.if not working as it should

Question

I am using sp.if in an internal function, then I call it in an entry point, but whatever I enter in sp.if, it always is read as "True". Why? And how to fix it? My code :

def is_something(self, contract):
    sp.if 1 == 2:
        return "Yes"
    sp.else:
        return "No"

@sp.entry_point
def updateSomething(self, params):
    sp.set_type(params, sp.TRecord(_id = sp.TNat, percentage = sp.TNat))
    sp.trace(self.is_something(sp.sender))

When the entry point is called, sp.traces writes "Yes" instead of no. Why?

Answer 1

sp.if gets translated to Michelson IF's, and cannot be used together with meta-programming e.g. ruturn statements since meta-programming gets applied before compilation.

Meta-programming (Applied before compilation, useful for creating contracts with multiple configurations)

if <condition>:
   do stuff...
else:
   do something else...

Applied at runtime

some_var = sp.local("some_var", 0)
sp.if <condition>:
   some_var.value += 1
sp.else:
   some_var.value = 0

Example on how to do it: https://smartpy.io/ide?cid=QmUWSVV6wnkDUF25thYSBPTJqWaATHeDELoQWwgh3ap6DV&k=17f3f11bcd5974c8d408

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