如何在 Python 3 中获取一个函数以返回我可以在另一个函数中使用的值？

Question

I need to design a game of snakes and ladders in python and for part of it, I need to be able to roll a dice and get a random value. For this, I have imported random and then written the function below. However, obviously, I then need to be able to use the dice value in other functions of the game. How do I get it so that the value python returns is retained and able to be used in another function.

Below is the function I have written for rolling the dice. However, when I then run this function and then afterwards try print(dice_value) , the program tells me that dice_value has not be defined.

Anybody able to help??

import random 
def roll_dice():
    dice_value = random.randint(1,6)
    print("Its a..." + str(dice_value))
    return dice_value

Answer 1

The variable dice_value exists only inside your function roll_dice() . It is a local variable . You need to call your function with:

my_variable = roll_dice()

Now the result of your function is stored in the variable my_variable , and you can print it.

Answer 2

You have to save the return value somewhere and then use it or pass it to another function.

For example:

>>> import random
>>> def roll_dice():
...     dice_value = random.randint(1,6)
...     print("[in roll_dice] Its a..." + str(dice_value))
...     return dice_value
... 
>>> obtained_dice = roll_dice()
[in roll_dice] Its a...1
>>> print("[outside roll_dice] Its a..." + str(obtained_dice))
[outside roll_dice] Its a...1

variable dice_value is a local variable inside the function space so you have to return and save it in another variable to continue using it

Answer 3

You can store the return value of your function roll_dice() in a variable that will in return store the value of the return variable (dice_value).

random_dice_value = roll_dice()

Note: You need to call the function after you have implemented it since Python is an interpreter language. It will execute the file line by line.

Answer 4

The problem is that you're trying to call the variable dice_value outside of its scope. If you still go on with your one liner print statement, you can do so by calling the function (that's returning the dice_value variable) as in:

print(roll_dice())