I am trying to make a RPG game using python but I am having trouble as I have to allow a user to receive a certain Item only once. If the user interacts with a NPC for the first time they should receive an item, if the user interacts with the same NPC again, they should receive a quote. Is there any way to prevent the NPC to give the user the same thing if they are interacted more than once?
def function():
print("What do you want to do?")
userInput = input("1. Talk to the blacksmith \n2. Leave\n")
if userInput == "1":
# if the user hasnt already received the sword:
print("the BLACKSMITH gifts you a sword")
else:
print("Hi, how can I help?")
function()
function()
CodePudding user response：
Sure, there are multiple ways.
You could have a mutable function, then your code would look like this:
def function(given_items=[]):
print("What do you want to do?")
userInput = input("1. Talk to the blacksmith \n2. Leave\n")
if userInput == "1":
# if the user hasnt already received the sword:
if not "sword" in given_items:
print("the BLACKSMITH gifts you a sword")
given_items.append("sword")
else:
print("Hi, how can I help?")
function()
function()
Word of caution regarding mutable arguments: https://florimond.dev/en/posts/2018/08/python-mutable-defaults-are-the-source-of-all-evil/
Or you could have a global flag or array, something like:
GIVEN_ITEMS = []
# SWORD_GIVEN = FALSE # You could also use a boolean instead of a list, the advantage with a list is that it allows you to keep track of all such items instead of having a boolean flag for every single item.
def function():
print("What do you want to do?")
userInput = input("1. Talk to the blacksmith \n2. Leave\n")
if userInput == "1":
# if the user hasnt already received the sword:
if not "sword" in GIVEN_ITEMS:
print("the BLACKSMITH gifts you a sword")
GIVEN_ITEMS.append("sword")
else:
print("Hi, how can I help?")
function()
function()
CodePudding user response：
If Sword is False than Player will receive a gift and record an entry that Sword is True (Present).In if function "and" Operator make sure that both conditions are True i.e. Sword is False.
Sword = False
def function():
print("What do you want to do?")
userInput = input("1. Talk to the blacksmith \n2. Leave\n")
if userInput == "1" and Sword == False:
# if the user hasnt already received the sword:
print("the BLACKSMITH gifts you a sword")
Sword = True:
else:
print("Hi, how can I help?")
function()
function()
CodePudding user response：
You can also look at changing the entire implementation of function() as part of executing it via a closure. The advantage here might be that the method itself keeps track of the proper implementation rather than using a "global" variable.
## -------------------------------
## A closure that encapsulates some internal methods and when called
## returns one of them that can be assigned to a more global variable
## that can then be called.
## -------------------------------
def build_blacksmith_conversation():
## -------------------------------
## The implementation we want if this is the first time
## -------------------------------
def first_time():
nonlocal active ## this variable is defined in the outer context
print("What do you want to do?")
userInput = input("1. Talk to the blacksmith \n2. Leave\n")
if userInput == "1":
print("the BLACKSMITH gifts you a sword\n\n")
## -------------------------------
## since you have the sword, reset the active implementation
## -------------------------------
active = not_first_time
## -------------------------------
## -------------------------------
## -------------------------------
## The implementation we want if this is not first time
## -------------------------------
def not_first_time():
print("What do you want to do?")
userInput = input("1. Talk to the blacksmith \n2. Leave\n")
if userInput == "1":
print("Hi, how can I help?\n\n")
## -------------------------------
## -------------------------------
## Set the active implementation
## -------------------------------
active = first_time
## -------------------------------
## -------------------------------
## return a method that when called calls whatever the "active" method is
## -------------------------------
return lambda : active()
## -------------------------------
## -------------------------------
## -------------------------------
## Create a new method blacksmith_conversation() that will initially use
## one implementation but after the sword is given will switch to a new one
## -------------------------------
blacksmith_conversation = build_blacksmith_conversation()
## -------------------------------
## -------------------------------
## Give the sword
## -------------------------------
blacksmith_conversation()
## -------------------------------
## -------------------------------
## offer help
## -------------------------------
blacksmith_conversation()
## -------------------------------
This will give you output that might look something like:
What do you want to do?
1. Talk to the blacksmith
2. Leave
1
the BLACKSMITH gifts you a sword
What do you want to do?
1. Talk to the blacksmith
2. Leave
1
Hi, how can I help?
CodePudding user response：
There are many ways to achieve this:
You can have a variable outside your function like:
Temp = True
And Make a variable change in your function something similar to this :
global Temp
Temp = False
So the actual code would be :
Temp = True
def function():
print("What do you want to do?")
userInput = input("1. Talk to the blacksmith \n2. Leave\n")
if userInput == "1":
# if the user hasnt already received the sword:
print("the BLACKSMITH gifts you a sword")
else:
print("Hi, how can I help?")
global Temp
Temp = False
while True:
if Temp != False:
function()
else:
print(Temp)
break