Your weapon.attacks method doesn't have an explicit return value, so it returns None. When you call print(equipment["weapon"].attacks()) you're printing out the return value, which is None. Either change the method to return the "your " + self.name + " blocked " + str(self.attack) + "\n" string, and then print it, or just call the method and let it do the printing, without printing the return value.
Basically change your last line to this:
#print(equipment["weapon"].attacks())
equipment["weapon"].attacks()
