如何从包含多个变量的函数中仅调用一个变量？

Question

So basically I am trying to create a hangman game, and as of right now I'm just trying to pass a variable from one function to another, though I'm confused on how to do so, here is my code:

import random

print("Welcome to Hangman!")

def wordSelection():
  words = ["test", "random"]
  wordChoice = random.randint(0, 1)
  selectedWord = words[wordChoice]
  print(selectedWord)
  return selectedWord

def guessWord():
  selectedWord = wordSelection()
  print(selectedWord)


wordSelection()
guessWord()

The question I have is basically, how am I able to call the variable 'selectedWord' from the wordSelection function and pass it into the guessWord() function?

I tried to at the bottom as you can see, however I just called the whole function again, instead of only specifically getting selectedWord rather than the whole function.

What could I do to ONLY get 'selectedWord' from WordSelection() rather than just getting the whole function - is this possible?

Answer 1

You are returning the selectedWord value from wordSelection() so you can just directly use it in your code. Although, i don't understand what are you trying to accomplish with this as guessWord function is redundant.

You can do something like this :

guessWord(wordSelection()) 

and define guessWord function like this :

guessWord(words) :

This will pass the value returned by wordSelection() ie value of selectedWord in function guessWord() .

Answer 2

You have a misunderstanding about how variables work, especially in Python.

In Python, a variable is simply a label that refers to a value that exists somewhere in memory. For example:

 x = 3
 # Now you can refer to the value `3` by the name x
 y = x
 # Now `y` refers to the *same* `3` that is in memory - it's not a copy!
 print(id(x))
 print(id(y))
 # Will print the same ID, but it will probably be different on your
 # system and mine

When you return a value from a function, you're not returning the name - you're returning effectively where the value lives. If you want to keep that value, you're going to have to give it a name:

def fun():
    result = 42
    print(id(result))
    return result

fun()  # Discards the return value
print(fun())  # prints the return value
print(id(fun))  # prints where the return value lives
value = fun()   # actually stores the return value by giving it a name
print(id(value))    # now you can use that value later!
print(value + 3)    # you can use it more times

So in your code, you want to call a function that gives you a random word, which you can do like this:

def word_selection():
    # Note I used snake case - see
    # https://www.python.org/dev/peps/pep-0008/#function-names
    # for more info
    words = ['test', 'random', 'python', 'awesome', 'something', 'completely', 'different']
    return random.choice(words)

In order to do anything with this value, you need to store it. It's returned wherever you call the function. In Python you call something by adding parenthesis () after it:

print(word_selection)  # Doesn't call the function
print(word_selection())   # Does call the function, then prints the result

So you can either require an argument on your guess_word function and pass it in:

def guess_word(word):
    # do whatever you need to do here
    print('Time to guess:', word)   # don't really give them the answer, though

guess_word(word_selection())   # you can call it like this

secret_word = word_selection()   # or store the value first
guess_word(secret_word)          # and then pass it to your function

---

Writing your program like that is probably a good exercise in seeing how that stuff works - but you could actually make it the same by doing something like this:

WORD_LIST = ['python', 'something', 'completely', 'different']


def guess_word(word):
    print('Time to guess the word:', '*'*len(word))

guess_word(random.choice(WORD_LIST))

Answer 3

Store the return value in a variable.

import random

print("Welcome to Hangman!")

def wordSelection():
  words = ["test", "random"]
  wordChoice = random.randint(0, 1)
  selectedWord = words[wordChoice]
  return selectedWord

def guessWord(selectedWord):
  selectedWord = wordSelection()
  print selectedWord