Python function not returning anything

Question

def equip(x):
 global bag_sword
 global bag_chest
 global bag_gloves
 global bag_helmet
 while x == "iron sword" and "iron sword" in bag:
 if bag_sword:
 print "You can't have 2 weapons equipped!"
 x = ""
 print "\nYou equip the iron sword.\n"
 bag.remove("iron sword")
 bag_sword.append("iron sword")

When I run this the first time, it works fine, but when I run it a second time nothing happens.

bag_sword is a list

test code:

bag.append("iron sword")
if input1[:5] == "equip":
 print input1[:5]
 equip(input1[6:])
 print input1[6:]
I type into the console 'equip iron sword'

I've tried using a variable in place of the input[]

(It isn't syntax)

• nwk: You function reads and mutates global variables, so it won't necessarily do the same thing each time it is called. What do you want to happen?
• Adam Burros: What this is supposed to do is add a weapon to bag_sword if nothing is there, and tell the player they' can't have 2 equipped if one is already there.

Answer 1

Here is how you can make the function work as described:

bag_sword = []
def equip(x):
 global bag_sword
 if x == "iron sword":
 if "iron sword" in bag_sword:
 print "You can't have 2 weapons equipped!"
 else:
 bag_sword.append("iron sword")
print bag_sword # Prints "[]".
equip("iron sword") # Prints nothing. Puts the string "iron sword" in bag_sword.
print bag_sword # Prints "['iron sword']".
equip("iron sword") # Prints "You can't have 2 weapons equipped!". bag_sword is unchanged.

• Adam Burros: I ended up fixing this with a few tweaks to yours. I don't know why I used a while loop, I've been at this for a few days now heh, thank you.

Answer 2

You can make nwk's solution more general (also try to get rid of global variables):

def equip(item, bag):
 if item in bag:
 print "You can't have 2 {}s equipped!".format(item)
 else:
 bag.append(item)
def main():
 bag_sword = []
 print bag_sword
 equip("iron sword", bag_sword) 
 print bag_sword
 equip("iron sword", bag_sword)
if __name__ == '__main__':
 main()

It also seems to me that a dictionary or class would be a better alternative than several bag lists:

def equip(item, slot, inventory):
 if inventory[slot] == item:
 print 'Already equipped.'
 else:
 inventory[slot] = item
 print item.capitalize(), 'equipped.'
def main():
 inventory = {
 'weapon': None,
 'gloves': None,
 }
 equip('iron sword', 'weapon', inventory)
 print inventory
 equip('iron sword', 'weapon', inventory)
if __name__ == '__main__':
 main()