How do I properly set these conditionals in Python? - python

I am VERY new to coding in general so this may come across as a stupid question.
Right now I am experimenting with conditional statements and trying to code a little decision based two-way path in the style of a text game, where the user is given two options and each option has a different outcome. Right now, the "if True" string is ALWAYS executed in the console, regardless of what the user types in. Why is this happening and how can I rewrite it to make the command happen correctly? Also, I thought I followed the instructions for pasting code here but it doesn't look quite right.
input ("Type 'left' if you want to go left and 'right' if you want to go right"
right = True
left = False
right = "right"
left = "left"
if True:
print("You have been eaten by a monster. Game Over!")
else:
print("Congratulations you have made it to the castle!")
else:
print("Error")```

There's no such thing as a stupid question!
In any programming language, when you come across an if-statement, you should read it as "if this statement evaluates to true, do this." So, in your example, writing
if True:
# do something
will always run that code, because True always evaluates to True!
It sounds like what you want to do is compare the player's input to some set string (in this case, "right" or "left"). The first thing you should know is that the input() function returns, as a string, whatever the user input before hitting enter. So, in this case, you might want to do something like
direction = input("Would you like to go left or right?")
Now, once the user inputs something and hits enter, whatever they entered will be saved in the variable direction. Now, we can compare the entered string to whatever we want. In this example, we would want something like
if direction == "left":
# do left stuff
elif direction == "right":
# do right stuff
else:
# they didn't enter a valid string!
I hope this helps. If you're just starting out on your programming journey, I would recommend looking up some Python tutorials online which are specifically made for beginners, and try finding one that suits your learning style. Best of luck!

Related

How to make a Dungeons and Dragons-esque skill check in Python?

I am trying to make a small text-based adventure game in Python IDLE, but I am running into some issues with having the game give a different response if the player rolls above or below the DC of a DND style preception check. I am very new to this so it's probably an easy fix. Here's the code.
I have no idea how to input the code into the question correctly so here is a picture.
BTW I did import random at the beginning of the code its just too far back to include in the screencap.
Your problem is you are not specifying what numbers the random module to choose from, in the line if random.randint > 10:. To fix this, put the numbers you want it to choose between. For example, if you want it to choose a random number between 1 and 20, your line would become if random.randint(1,20) > 10:.
You will also want to do this for the other line, which reads if random.randint < 10:.
welcome to SO,
Please read the minimal reproducible example guide posted in the comments by D.L. First thing I would do is to post the actual code, because if the link expires, then others viewing this post with a similar issue cannot figure out what was the given example, and how it was solved.
With logistics out of the way, to fix the error you are specifically receiving is to put what is rolled in a variable.
Here are a few things I would change to make your code clear
# Some string that receives yes or no
room_2_input = ("...")
# if condition is yes
if room_2_input == 'yes':
# Put it in a variable
roll = random.randint(1,20)
# You do not have to format a string this way, but I think it makes it easier
print('You rolled {}'.format(roll)
# Put this condition within the first if, because you don't
# need to execute it if they do not choose to roll
# Neither of your original condition has inclusivity, so if 10 is rolled,
# your program will do nothing, because neither condition would be met
if roll >= 10:
'''do stuff'''
# I would only include elif < 10 if you are specifically looking for > 2
# outcomes, but your outcome appears to be binary, either above or below 10
else:
'''do stuff'''
The reason you would not do a random.randint(1,20) > 10: check in your second if statement is because you would be executing a different roll than your first one.

Exiting a python application for 'GAME OVER'

I would like to know why this code does not work; it should exit at the "GAME OVER" point, but it continues to my next defined function.
I have tried other variations on exit() such as: sys.exit(), quit() and SystemExit.
run_attack = input("What do you do: Run/Attack\n")
run = ['run', 'Run', 'RUN']
attack = ['attack', 'Attack', 'ATTACK']
run_attack = 1
while run_attack < 10:
if run_attack == ("run") or ("Run") or ("RUN"):
print ("You turn to run from the wolf but he quickly pounces
you...")
time.sleep(2)
print("You are quickly ripped apart and just about get to see
yourself be eaten.")
print("GAME OVER")
break
exit() #This is where the game should exit, yet after input it
continues to the next function
elif run_attack == ("attack") or ("Attack") or ("ATTACK"):
print("You brace yourself for a bite and have no time to reach"
"for any kind of weapon form your backpack.")
time.sleep("2")
input("You clock the dog hard, twice on the muzzle.")
print("The dog recoils in pain and retreats back to the woods.")
print("You quickly start running as you assume there will be a den in the woods.")
break
else:
input("Type Run or Attack...")
You have several problems in your code; why did you write this much without testing it?
First, you read the user's input, immediately replace is with 1, and then try to test it (incorrectly) as if it were still a string. Your posted code has several syntax errors, so I have some trouble reproducing the problem. However, the immediately obvious problem is here:
break
exit() # This is where ...
You can't get to the exit statement, as you break from the loop just before you can get there.
I strongly recommend that you back up to a few lines and use incremental programming: write a few lines at a time, debug those, and don't continue until they do what you want.
Also look up how to test a variable against various values. Your if statement is incorrect. Instead, try the list inclusion you're trying to set up:
if run_attack in run:
...
elif run_attack in attack:
...
I took the liberty of rewriting your whole program to show you a few things wrong with it and a few tricks. I've done it without the loop, since you never use it anyway... you can add the while loop later once you've mastered it, but you should really go back to basics on some things here:
run_attack = input("What do you do: Run/Attack\n")
if run_attack.lower() == "run":
print("""some
stuff
with
multiple
lines and GAME OVER""")
exit()
elif run_attack in ("attack", "Attack", "ATTACK"):
print("""some
stuff
with
multiple
lines""")
else:
input("Type Run or Attack...")
Some notes:
Using """ for strings enables you to write multiple lines without multiple print statements
Using str.lower() on strings makes everything easy to compare because you only have to compare it to the lowercase version of each string. However for attack you can notice I used a different inclusion test, without multiple conditions. Either way works here.
Like the other answer here (and many comments), you should use only exit() to leave the program entirely, or only break to exit the loop and continue to other code that's beneath the entire loop.
When you rewrite your loop, with a condition like while number_of_turns < 10 don't forget to add 1 to the number of turns on each loop, otherwise that condition is always True and you'll have an infinite loop...
I'm actually quite surprised this code had any resemblance to the behavior you expected from it, my suggestion is to go back over to the basics of python, learn loops, string methods, basic commands. The rest is already said in the other answer here (which is better than mine, frankly) just wanted to add some ideas.

Python Function requesting input doesn't execute if statement - no error shown

I thoroughly searched for an answer to my question but couldn't find anything that would explain my results. I truly hope that anyone of you can point me in the right direction.
At the moment I am trying to program a text-based adventure game using Python 3 in order to better understand the language.
While doing so I created a function that should ask the user for input and print a specific statement depending on the users input. In case the users input is invalid the function should then keep asking for input until it is valid.
Unfortunately the function only seems to keep asking for input, without ever executing the if/elif statements within the function. Due to no errors being shown I am currently at a loss as to why this is the case...
print("If You want to start the game, please enter 'start'." + "\n" +
"Otherwise please enter 'quit' in order to quit the game.")
startGame = True
def StartGame_int(answer):
if answer.lower() == "start":
startGame = False
return "Welcome to Vahlderia!"
elif answer.lower() == "quit":
startGame = False
return "Thank You for playing Vahlderia!" + "\n" + "You can now close
the window."
else:
return "Please enter either 'r' to start or 'q' to quit the game."
def StartGame():
answ = input("- ")
StartGame_int(answ)
while startGame == True:
StartGame()
You fell into the scoping trap: you are creating a new variable startGame inside the function that is discarded after you leave it. You would instead need to modify the global one:
def StartGame_int(answer):
global startGame # you need to specify that you want to modify the global var
# not create a same-named var in this scope
# rest of your code
This other SO questions might be of interest:
Python scoping rules
Asking the user for input until they give a valid response
Use of global keyword
and my all time favorite:
How to debug small programs (#1) so you enable yourself to debug your own code.
The last one will help you figure out why your texts that you return are not printed and why the if does not work on 'r' or 'q' and whatever other problems you stumble into. It will also show you that your if are indeed executed ;o)
Other great things to read for your text adventure to avoid other beginner traps:
How to copy or clone a list
How to parse a string to float or int
How to randomly select an item from a list

Learn Python the Hard Way - Exercise 36 - if else die function

The second rule for If-Statements here, which has me confused states that:
If this else should never run because it doesn't make sense, then you must use a die function in the else that prints out an error message and dies, just like we did in the last exercise. This will find many errors.
Here's the code from the last exercise:
def dead(why):
print why, "Good job!"
exit(0)
def start():
print "You are in a dark room."
print "There is a door to your right and left."
print "Which one do you take?"
choice = raw_input("> ")
if choice == ‘left’:
bear_room()
else:
dead(‘You stumble around the room until you starve.’)
Is it essentially saying that you must successfully terminate the program if a condition is not met?
Yes, the idea is:
import sys
def die(msg):
print msg
sys.exit(1)
if condition:
# do stuff
else:
die('This cannot happen!')
You could also use an assert instead, or raise an exception, or anything else that would fail catastrophically. This helps you validate at runtime that the clause you didn't expect to execute, really didn't run.
IMHO you shouldn't get too hung up on how this die is done, exactly. The important point the referred text tries to make is that when you're sure some condition is true, you might as well assert it forcefully so that you can catch runtime bugs.
The guide is trying to show you that you can see the choice that a user gives when it's something that you don't check for in your if statement. If your else looks like:
else:
dead(choice)
You will be able to see what the user input that you didn't expect.
The problem is that the syntax only allows for "Left", when the prompt allows entry of anything. In other words, if I enter "Bob", I will starve. I should be trapping for anything that isn't appropriate and "die"ing at that point (or helping the user make an appropriate decision).
This is an attempt at teaching error handling and die. You would rewrite it such that you allow accurate entry or die (no exit). If you don't choose left, there is no other choice even though the prompt states there are two choices.
If you truly expect only 'left' to be added, a better way of checking for unexpeted input would be
if choice != ‘left’:
dead(‘You stumble around the room until you starve.’)
bear_room()
That way you still validate that the input is what you expected, but it saves indentation and space for the main logic.

How to print variable on multiple lines and call on a single piece of code many times in Python?

1.I'm using break to break out of a loop, but I don't know how to make the program keep going no matter what unless this happens. Just typing in while: is invalid (or so the progam tells me) and I want the game to keep going even if the user types in an emptry string.
2.Is there a way to not have to re-type a bit of code every time I need it? I have a bunch of responses for the program to spit out that I'll have to use many times:
if action[0]=='go':
print("You're supposed to go to David!")
elif action[0]=='look':
print("You can't see that")
elif action[0]=='take':
print("You don't see the point in taking that.")
else:
print("I don't recognise that command")
Where action is a list from the player's input. Or do I just have to type it out again each time?
I don't know how to define a function that does the above, and I'm not even sure that's what I'm supposed to do.
3.Some story descriptions I'm using are a very long stings and I don’t want players to have to scroll sideways too much. But I want to just define them as variables to save myself some typing. Is there a way around this. Or do I just have to type it out every time with
print(“““a string here”””)
4.If the string starts with 'look' and has 'floor' or 'mess' or 'rubbish' in it, I want it to print a certain output. This is what I currently have:
if action[0]=='look':
if 'floor' in action or 'rubbish' in action or 'trash' or 'mess' in action:
print('onec')
elif 'screen' in action or 'computer' in action or 'monitor' in action:
print('oned')
elif 'around' in action or 'room' in action or 'apartment' in action:
print('onee')
elif 'david' in action or 'tyler' in action or 'boy' in action or 'brat' in action or 'youth' in action:
print('onef')
break
else:
print("You can't see that")
It prints 'onec' for any input beginning with 'look'.
The while statement requires a condition.
You can call the same instructions over and over using a function.
"String literals can span multiple lines in several ways"
Use strategically-placed print statements to show the value of action, e.g. after if action[0]=='look'
Lastly, please don't add any more items to this question. Rather ask a new question. This site has somewhat specific rules on that sort of thing.
To make an infinite While loop, use while True:.
You could use a dict to store common action strings and their responses.
Just register the string first, then when the input come, change it:
command = "nothing"
command = input("Enter command: ")
while command:
Or just simply:
while True:
Yes, think about it by yourself.. Okay, why not put it in list responses?
If it is really long, put it in a file. Read it when you need it using open(). More on File Processing
This will help you shorten your code, making it easier to read, and makes it more efficient.
while requires a condition that it has to evaluate. If you want it to loop forever, just give it a condition that always evaluates to True, such as 4>3. It would be best for everyone if you just used while True:, which is the clearest option.
For this specific case, I would recommend using a dict() and its .get() method. Something like this:
action_dict = {'go':"You're supposed to go to David!",
'look':"You can't see that",
'take':"You don't see the point in taking that."
}
print(action_dict.get(action[0], "I don't recognise that command")
would replicate what you have going on right now.
See the link provided by cjrh here: http://docs.python.org/3.3/tutorial/introduction.html#strings
Our mind-reading powers are a bit off in October, we'll need some more information other than "it does not work" to help you with that.

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