Python: Subtracting from definitions/lists?

Question

In this code I am giving the user a few different guns. they encounter an enemy and are asked which gun they would like to use. this is where I get stuck. after they use the gun i try to subtract 1 from that specific gun's ammo count. (Which I don't know how to do...) And after that, I try to print out what weapon was used and what its ammo count is now at. I described it a little more in the code. Any help is appreciated!!!! :D
https://code.sololearn.com/camY2OQRav8W/?ref=app

Answer 1

guns = {"pistol": 6, "sniper": 4, "rocket launcher": 2}

print ("there is a monster in front of you!")
print ("use a weapon to kill the enemy?")
user_resp = raw_input("yes/no\n")
if "yes" in user_resp:
print ("which weapon would you like to use?")
print (guns)
user_resp = raw_input("")
if user_resp in guns:
print ("you shot your " + str(user_resp))
# update will not increment the value, instead try
# guns.update({"user_resp": -1})
guns[user_resp] -= 1
#this line is where im trying to subtract one ammo
#from the weapon the user chose.

print ("your " +user_resp+ " now has " + str(guns[user_resp]))
#im not sure how to write what weapon
#the user chose. and how to write the subtracted ammo count.

Answer 2

looks good! thanks!! :)