I’m curious about the recommended way to return a value for instance methods in Python. I’m sorry if this comes across as a rather trivial question, but I can’t seem to find a proper answer on google/sx/so.

Option 1:

class Cla:     def __init__(self):         self.var = False      def inst_mtd(self):         var = True         return var      def inst_2(self):         self.var = self.inst_mtd()    # or in init if desired 

Option 2:

def inst_mtd(self):     self.var = True 

Option 3:

def inst_mtd(self):     self.var = True     return self.var  def inst_2_or_init(self):     self.var = self.inst_mtd() 

My concerns are that 1 might result in confusion between local and instance variables, if the whole point of inst_mtd is to modify self.var and not actually deal with another variable called var. For 2, I’m under the impression that this constitutes a side-effect, which should be avoided? But 3 just seems unnecessary, although it does work well with return type annotations, especially when the type (not recommended) or elements within are changed in inst_mtd.

Thanks!