A toy assembler written in Python

assembler.py

class Assembler:
    def __init__(self, program):
        self.program = program
        self.registers = {}
        self.program_counter = 0
        
    def run(self):
        while self.program_counter < len(self.program):
            fn_name, *args = self.program[self.program_counter].split(" ")
            fn = getattr(self, fn_name)
            fn(*args)
            
    def increment_program_counter(fn):
        def wrapper(self, *args):
            fn(self, *args)
            self.program_counter += 1
            
        return wrapper
    
    @increment_program_counter
    def mov(self, register, value):
        self.registers[register] = self.register_to_value(value)
    
    @increment_program_counter
    def inc(self, register):
        self.registers[register] += 1
    
    @increment_program_counter
    def dec(self, register):
        self.registers[register] -= 1
        
    def jnz(self, test_value, inc_value):
        test_value = self.register_to_value(test_value)
        inc_value  = self.register_to_value(inc_value)
        
        if test_value != 0:
            self.program_counter += inc_value
        else:
            self.program_counter += 1
            
    def register_to_value(self, value):
        if self.is_integer(value):
            value = int(value)
        else:
            value = self.registers[value]
            
        return value
        
    def is_integer(self, n):
        try:
            float(n)
        except ValueError:
            return False
        else:
            return float(n).is_integer()