Why is str not callable

def TakeHoodie():
TakeHoodie=input("Would you like to take the Bieber Hoodie? Y/N ")
if TakeHoodie.upper == "Y":
bp.append("Bieber Hoodie")
lookIn()
elif TakeHoodie.upper == "N":
lookIn()
else:
print("You can't do that and we don't tolerate that language!")
TakeHoodie()
def lookIn():
lookIn=input("Would you like to check the fridge? Y/N ")
if lookIn.upper == "Y":
print("You find a glowing bottle of Red Bull in the fridge.")
stealBull()
elif lookIn.upper == "N":
print("You can hear the dinosaur stomping and the shack starts to fall")
else:
print("You can't do that and we don't tolerate that language!")
lookIn()
:trytofly: