How to remove those None ?

1 gen = ("f", 'M', "female", "Male", "male", "F", "m", "m", "male", "Female", "x"1 2 3 # Start your code below 4 gen2=0 5 for i in range(len(gen)): 6 if gen[i]=="f" or gen[i]=="F"or gen[i]=="female" or gen[i]=="Female": 7 print(gen2.append(0)) 8 9 10 elif gen[i]=="m" or gen[i]=="M"or gen(i)=="male"or gen[i]=="Male": 11 print (gen2.append(1)) 12 13 print (gen2) None None None None None None None None None None [0, 1, 0, 1, 1, 0, 1, 1, 1, 0]