Question

Recently I’ve been creating a game but I’m having a problem. To calculate what you’ve hit on an enemy it uses the variable sword.

At this point the player may or may not have purchased a sword, therefore I get an error that says: “variable not declared”. Is there a way to work around a variable that hasn’t been declared yet?

Answer 1

You have two options.

The first is to ensure that a player always has a sword variable. Set it to None before the player obtains a sword and, when you need to know whether the player has a sword, check whether the variable is None:

 sword = None

 # do lots of stuff here

 if sword is None:
    print 'Hey, no sword!'
 else:
    print 'Chop, chop, chop!'

Another way to write this if sword is not allowed to be an empty string or an integer value of 0 is:

 if sword:
    print 'Chop, chop, chop.'

Your second option is to wrap every reference to the sword variable in a try block and swallow the NameError that might be raised:

 try:
    if sword == 10:
        print 'Choppity chop chop chop.'
 except NameError:
    pass

The first solution is (much) better.