In Python, how to set value for one __init__ variable based on another?

Question

def __init__(self):
    #self.data = []
    self.random_word = random.choice(open("EnglishDictionary.txt").readlines()).strip()
    self.length_notice = "The word you're guessing is {} letters long.".format(len(random_word))

This just returns the error: Name 'random_word' is undefined

Answer 1

You set self.random_word , not random_word , so you need to use self.random_word :

self.length_notice = "The word you're guessing is {} letters long.".format(len(self.random_word))
                                                                   # Add self. ^^^^^

Answer 2

Just use it:

def __init__(self):
    #self.data = []
    with open("EnglishDictionary.txt") as f:
        msg = "The word you're guessing is {} letters long."
        self.random_word = random.choice(f).strip()
        self.length_notice = msg.format(len(self.random_word))

Ask yourself, though, if self.random_word really needs to be an instance attribute, or if random_word can simply be a local variable inside the function, like msg .