How do Arguments and Parameters Work in Python? [closed] - python

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I have looked all over Stackoverflow and I can't find an answer, and all the web tutorials just go right over my head. I have a functioning code that I don't understand
import random
import time
def displayIntro():
print('You are in a land full of dragons. In front of you,')
print('you see two caves. In one cave, the dragon is friendly')
print('and will share his treasure with you. The other dragon')
print('is greedy nd hungry, and will eat you on sight.')
print()
def chooseCave():
cave = ''
while cave != '1' and cave != '2':
print('Which cave will you go into? (1 or 2)')
cave = input()
return cave
def checkCave(chosenCave):
print('You approach the cave...')
time.sleep(2)
print('It is dark and spooky...')
time.sleep(2)
print('A large dragon jumps out in front of you! He opens his jaws and...')
print()
time.sleep(2)
friendlyCave = random.randint(1, 2)
if chosenCave == str(friendlyCave):
print('Gives you his treasure')
else:
print('Gobbles you down in one bite!')
playAgain = 'yes'
while playAgain == 'yes' or playAgain == 'y':
displayIntro()
caveNumber = chooseCave()
checkCave(caveNumber)
print('do you want to play again? (yes or no)')
playAgain = input()
I don't understand the def checkCave(chosenCave): parts, why does the argument say chosenCave?
Can someone explain please?

In the function
def checkCave(chosenCave):
...
chosenCave becomes a local variable that you passed to the function. You can then access the value inside that function to process it, provide whatever side-effects you're looking to provide (like printing to the screen, as you're doing), and then return a value, (which if you don't do explicitly, Python returns None, its null value, by default.)
Algebraic Analogy
In algebra we define functions like this:
f(x) = ...
for example:
f(x) = x*x
In Python we define functions like this:
def f(x):
...
and in keeping with the above simple example:
def f(x):
return x*x
When we want the results of that function applied to a particular x, (e.g., 1), we call it, and it returns the result after processing that particular x.:
particular_x = 1
f(particular_x)
And if it returns a result we want for later usage, we can assign the results of calling that function to a variable:
y = f(particular_x)

The name chosenCave appears to have been chosen to describe what it represents, namely, the cave the player chose. Were you expecting it to be named something else? The name isn't required to match or not match any names located elsewhere in the program.

Related

Unable to figure out this issue with a choice part of a simple text game im making

What I am trying to get it to do is give an initial choice about a "vial" that the player stumbles across. If the player picks it up, I want it to say something like "you acquired water" and then end. If they say No I just want the code to end so that they can proceed in the game. My trouble comes when I try to account for errors (like if someone puts in a 't' rather than a "Yes" or a "No". I have tried many different models and none of them seem to work. Here is an example of how I want it to behave:
If answer is yes:
You find a vial would you like to pick it up?
y
You have acquired 0.4 oz of water
You continue your journey
If answer is No:
You find a vial would you like to pick it up?
n
You continue your journey
If the answer is invalid:
You find a vial would you like to pick it up?
t
no you really need to decide this
t
You were killed
Game over
would you like to restart this section?
(and then tying in es would restart from the vial question)
My Current code:
keword = False
answer_yes = 'y' and 'yes' and 'Yes'
answer_no = 'n' and 'no' and 'No'
while not keword:
print('water. pick up?')
question = input( )
if question == answer_yes:
print('You have picked up 0.4 oz of water')
answered = True
keword = True
if question == answer_no:
answered = True
keword = True
else:
answered = False
keword = True
while answered == False:
print('no you need to answer')
recon = input( )
if recon == answer_yes:
print('You have picked up 0.4 oz of water')
answered = True
if recon == answer_no:
answered = True
else:
print('You have died the trees ate you. That sucks.')
print('would you like to restart?')
restart = input( )
If any of you have an answer to this that would be cool!
Setting answer_yes to 'y' and 'yes' and 'Yes' will not work, as and is a boolean operator, so it only works with True and False values.
The code you're looking for is:
answer_yes = ['y','yes']
answer_no = ['n','no']
and for your if statements, instead of if question == answer_yes: use if question.lower() in answer_yes.
Enclosing a group of values in square brackets seperated by commas creates a List, and using the in operator checks if a given item exists in a list.
The question.lower() converts it to lowercase, removing the need for including the capitalised versions in the lists.

Choose your own adventure - choice function?

I'm working on a choose-your-own-adventure game in Python to try to learn how to code. I might be doing this entirely wrong, but I thought rather than just nesting if-elif-else statements endlessly, I could write some sort of function that would be a template for all choices in the game.
My ideas was to have every decision in a given scene to generate two lists - choices and outcomes. The "multitemplate" function would then load the choose and outcomes lists, present the options to the player, take in the answer, and call the correct function for the outcome given.
My issue is that the outcome list is a list of functions, which Python doesn't seem to like. It says I've not defined the functions properly, but when I define my outcome functions before calling "multitemplate", it just prints them first.
Here's my code:
#Function to allow the adventurer to make choices
def refusal():
print("You stop at the roadsign you passed on your way into town. There are only two directions - towards Tarroway, or towards Angion, the town from whence you came.")
def guards():
print("The guards stop you.")
def theinn():
print("You follow the joyful chatter down the deserted street. Its source is a squat, one story building. A sign above the door reads \"The Forked Tongue\"")
choose = ["I walk towards the merry sounds.", "I turn on my heels and head back where I came from.","I stay where I am and watch the night quietly."]
outcome = [theinn(), refusal(), guards()]
def multitemplate(choose,outcome):
global mychoice
global carryon
for x in range(len(choose)):
print (f"{x+1}) " + choose[x], end="\n")
mychoice = (input())-1
while True:
if (mychoice) in range(len(choose)):
carryon = True
outcome[mychoice]
carrion()
else:
print("Please enter the number of the choice you wish to make.")
carryon = False
mychoice = int((input()))-1
I'd appreciate any input on how this should work properly, or if I'm going down a completely blind alley here.
Thanks!

How to have a function feed another function's input [closed]

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I'm making a hangman game and testing how different letter picking algorithms fare, but to do this, the guessing algorithm function has to feed a letter into the hangman function's input('Select a letter').
How do you make it so that a function detects when another function is waiting for an input ?
Assuming you are doing input() in a loop inside your hangman function, you could switch that to a yield and let an external function drive input as needed. In this example I have a hangman function that uses yield to get data. Now its a generator and driving function can use next and the generator's .send method to pump data into it.
def hangman(chances=5):
for i in range(chances):
letter = yield "prompt"
if letter == "quit":
yield "quit"
return
print("letter", letter)
# do all the things
solved = False
if solved:
yield "solved"
yield "failed"
def command_line_prompt_hangman():
feeder = hangman()
state = next(feeder)
while state == "prompt":
state = feeder.send(input("Next letter: "))
def test():
# after years of testing the best algorithm is
test = ['a', 'b', 'c', 'd', 'e', 'f']
feeder = hangman()
assert next(feeder) == "prompt"
for count, letter in enumerate(test, 1):
state = feeder.send(letter)
if state == "solved":
print("did it in ", count, "tries")
break
if state == "failed":
print("exceeded count")
break
command_line_prompt_hangman()
test()
Instead of using the input function, write a custom function to pull an output from whatever algorithm you are using. That would look something like this:
user_input = algo_obj.get_input(game_state)
In this case, algo_obj would be an object storing the current state of the algorithm/generator (if such a state exists, otherwise you can just call the function normally). game_state would be some representation of the game's current state (available letters, the word-form -- ie. blanks & letters).
You can then feed user_input to your Hangman function.
This should be as simple as:
Define both functions.
Pass one function return value to the other one as argument.
This can be done by using input() as according to this
e.g. Define the functions
def first_function():
input_variable = input("Please enter some data")
return input_variable
def second_function(a):
print(a) # Do some calculations here
And use them:
second_function(first_function())
I wouldn't say that this is necessarily the best way to go about but it solves Your problem. If You would like to receive a more detailed answer please provide code samples.

Trying to return a True variable from a nested chain of functions (in Python)...

I'm trying to write part of an adventure game program in Python, and though I have most of it down, I'm stuck at trying to return a value declared as "True" at the end of one branch in the function chain. Basically, this is a fight against a monster, which you can win if you choose the right options. If you win, you obtain the bow that he was guarding. Here is the code of the fight:
#The first line imports all the text displayed in the game, saved in gametext.py
#For purposes of clarity, all text has been saved to variables imported by the file.
#Any variable that is not "HaveBow", "why" or declared by a raw_input() is actually text.
from gametext import *
def BG_fight():
print BowGuardIntro
print InitOptions
BGfirstmove = raw_input('> ')
if BGfirstmove == "1":
spearfight()
elif BGfirstmove == "2":
dead(BGUnarmed1)
else:
dead(BGUnarmed2)
def spearfight():
print GotSpear
print SpearFight
spearact = raw_input("> ")
if spearact == "1":
blindfight()
elif spearact == "2":
dead(SeeChest)
elif spearact == "3":
dead(SeeArms)
else:
dead(NoUseSpear)
def blindfight():
print BlindFight
followblow = raw_input("> ")
if followblow == "1":
print Victory
HaveBow = True
return HaveBow
elif followblow == "2":
dead(BlindArms)
else:
dead(BlindNoKill)
def dead(why):
print why
exit(0)
BG_fight()
(If people are interested, I can also produce the contents of the gametext file, though I would rather not as it is lengthy and has nothing to do with the problem I'm having)
As you can see, only one branch there offers the winning condition (which would give the HaveBow = True value that I want to return), and it is nested two functions deep and part of an if-statement. What I want to know is how I return that "HaveBow = True" value back outside the function chain, so it can be used in other parts of the game? If I try to code:
HaveBow = blindfight()
print HaveBow
at the end of the code and try to run it, it just makes me repeat that part of the game twice, before declaring "True". Same goes if I try BG_fight() instead of blindfight(). But I don't want that; I just want the "True" for "HaveBow" so I can use the condition "HaveBow = True" in other parts of the game.
In short, my question is whether or not it's possible to return a value from a nested function chain without repeating the code of that chain, and if so, how?
Thanks.
You can only return a value, not a name and a value. In other words, you cannot "return HaveBow = True"; all you can do is return True. There's no way to return a value and at the same time assign it to a variable that exists outside the function. If you want to assign the value, you need to do it outside the function.
From what you say, it sounds like you want HaveBow to be a global variable that you can use anywhere in your program. In that case, you can change your code in blindfight to do:
if followblow == "1":
global HaveBow
print Victory
HaveBow = True
Note that in this case you do not need to return the True value -- you just directly assign it to a global variable.
Ultimately there are better ways to structure your code, but those issues are out of the scope of this question. For the moment, I would suggest that, if you have global state like HaveBow that you want to be able to use "anywhere else in the game", you should make those global variables using global as I showed in my example. As you progress learning more programming, you will gradually learn why using global variables is not usually the best idea, but for the purposes of this program it is the simplest solution.

Pokemon Battle in Python [closed]

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I am not that great with OOP but I am stuck right now. First off, I don't think I set the damage correctly and I am trying to figure out how to output the damage to the user. Any help would be appreciated.
#Pokemon Battle
import random
from time import sleep
from array import *
class Pokemon(object):
def __init__(self, xname, xhealth):
self.name = xname
self.health = xhealth
def damage1(self,Charmander):
Squirtle.health - self.damage
def damage2(self,Charmander):
self.health - Squirtle.damage
print ('What is your name?')
name = input()
print ('Hello '+name+'! You are about to enter a pokemon battle.')
sleep(1)
print ('A wild Charmander appeared!')
sleep(1)
print ('You sent out Squirtle!')
sleep(1)
print ('Do you want to fight(1) or run away(2)?')
choice = input()
damage = random.randint(1,50)
damage = str(damage)
if choice == '1':
print ('You dealt '
sleep(1)
print ('Charmander did ')
if choice == '2':
print ('You ran away.')
else:
print ('Not a valid response.')
Right off the bat, you can use String Formatting to insert variables in strings.
#old way
some_string = "the value of 2+2 = %i",4
#new way
some_string = "the value of 2+2 = {}".format(4)
For your code, try:
if choice == '1':
print("You dealt {}".format(damage_goes_here))
However there's deeper issues with your code. Let me look more and I'll edit.
Object Oriented Programming
Okay so the first problem you have is that you never actually MAKE anything. When you write class SomeClassLikePokemonOrWhatever: what you're doing is making a template of something. It's like making a cast or a mold of an item before you make it -- you want all your Pokemon (or whatever) to be alike, so you make a mold of them and cast them all from the same mold. You can decorate and unique-ify them after that, but we want them all to be the same, basically. So instead, you should have something like this:
class Pokemon:
def __init__(self,name,base_hp):
self.name = name
self.base_hp = base_hp
#the __init__ function gets called when you "instantiate" (e.g. actually MAKE)
#whatever object the class is describing. In most cases, all it does it set
#the starting properties of the object based on how you define it (like this)
#you could also say all pokemon are beautiful, and add something like
self.description = "Absolutely GORGEOUS darling!"
#that will be constant for every pokemon you make through this definition.
#you said you wanted damage to be random between 1-50, so we don't need to add
#that statistic to the class.
That covers the definition of the object, but it still doesn't DO anything. In fact, let's let it do something, shall we? We want it to attack. What's a pokemon that doesn't fight? So let's give it a function (in a class, we call functions "methods.")
def attack(self,target):
#in this method we'll teach the pokemon how to fight
damage = random.randint(1,50) #don't forget to import random to do this
target.hp -= damage
Now you need to make some stuff. You defined what a Pokemon is and what it can do, but you haven't made one. Let's make some. Luckily it's easy.
my_awesome_pokemon = Pokemon("Charizard",200) #you give the args in the same order __init__ takes them
your_sucky_pokemon = Pokemon("Magikarp",20) #same deal here.
That makes two pokemon, one for you and one for them. If you wanted a whole belt full, you could define an array all_my_pokemon and fill it with Pokemon objects defined in this way. Just something to think about.
To actually fight, you'd tell your pokemon to attack.
my_awesome_pokemon.attack(your_sucky_pokemon)
#just that easy, now display how much damage it did....WAIT STOP WE HAVE A PROBLEM!
since you want random damage every time, you can't access it with something like my_awesome_pokemon.damage, since it's a local variable it dies when the attack method ends. You can, however, return that value in the method and use that.... Let's change our method.
def attack(self,target):
damage = random.randint(1,50)
target.hp -= damage
return damage #now we have some way to access how much damage was done from our main thread
Now to display it, we can do
damage_done = my_awesome_pokemon.attack(your_sucky_pokemon) #since .attack() returns the damage it deals, this sets damage_done to a sane amount.
print("My pokemon {} dealt {} damage to {}".format(my_awesome_pokemon.name,damage_done,your_sucky_pokemon.name))
Does that make sense?
I really think you should brush up on your OOP and then come back to this problem, because this is definitely a decent problem to practice on.
First of all, you set damage, and then set it again randomly:
self.damage = xdamage
self.damage = random.randint(1,50)
And this function is left open, which is going to cause compile issues, besides for the fact that you're missing any actual data!
print ('You dealt '
sleep(1)
print ('Charmander did ')
You're going to want to call your damage variable and Charmander's damage variable; think about how that is accomplished in OOP.

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