In this code
money = .3
Things = ["Nothing"]
def main():
print "go to buy things"
print "Current Money %s" % (money)
print "Things you have:"
for item in Things:
print item
wait = raw_input()
buythings(money)
def buythings(money):
print "Type Buy to buy things"
buy = raw_input()
if buy == "buy":
money = money - .3
Things.append("Things")
main()
else:
print "you bought nothing"
print ""
main()
Why after buying the things does the money not go down? This has been a problem to me for a while now and I cant seem to understand how the scope works in this situation.
The global variable money is shadowed by the function parameter money in buythings(money) function. You should remove the parameter for it to work:
def main():
global money
global Things
...
def buythings():
global money
global Things
...
However, A better approach, as alfasin pointed out, would be passing money and Things as parameters to both functions and not using global keyword at all:
def main(money, things):
...
for item in things:
print item
wait = raw_input()
buythings(money, things)
def buythings(money, things):
...
if buy == "buy":
money = money - .3
Things.append("Things")
main(money, things)
else:
...
main(money, things)
>>> money = .3
>>> Things = ["Nothing"]
>>> main(money, Things)
Hope this helps.
You can use a global variable in other functions by declaring it as global in each function that assigns to it:
money = 0
def set_money_to_one():
global money # Needed to modify global copy of money
money = 1
def print_money():
print money # No need for global declaration to read value of money
set_money_to_one()
print_money() # Prints 1
In your case :
def buythings():
global money
Python wants to make sure that you really know what you're
playing with by explicitly requiring the global keyword.
