Why this code doesn't work perfectly plz help

Question

import random
def game(comp,u):
if comp=="snake":
if u=="water":
return False
else:
return True
elif comp=="gun":
if u=="snake":
return True
else:
return False
elif comp=="water":
if u=="gun":
return False
else:
return True
elif comp==u:
return None
print()

com=(" choose gun, water, or snake")
randomno=random.randint(1,3)
#print(randomno)
if randomno==1:
computer="gun"
elif randomno==2:
computer="water"
elif randomno==3:
computer="snake"
you=str(input("choose any one gun, water, or snake -->"))
a=game(computer,you)
print(f"computer choose --> {computer}")
print(f"you choose --> {you}")
if a==None:
print("game tie")
elif a==True:
print("you won")
elif a==False:
print("you lose")

Answer 1

Could i please know where the problem is exactly. Is it an error, or is it not doing what you want?

Answer 2

There is no error but i didn't get desire output

Answer 3

Could i please know what the aim is?

Answer 4

Did you ever played snake, water and gun game Or stone, paper, scissors game