Python 2.7 值错误 : Need more than 0 vales to unpack (Learn Python the Hard Way Ex 41)

Question

我已经阅读了所有与解包错误和 LPTHW ex 41 相关的答案，并重新检查了我的代码一个小时，但我仍然没有得到我的错误。

以下是我的代码:

import random
from urllib import urlopen 
import sys

WORD_URL = "http://learncodethehardway.org/words.txt"
WORDS = []

PHRASES = {
"class ###(###):":
    "Make a class named ### that is-a ###.",
"class ###(object):\n\tdef __init__(self, ***)" :
    "class ### has-a __init that takes self and *** parameters.",
"class ###(object):\n\tdef ***(self, @@@)":
    "class ### has-a function named *** that takes self and @@@ parameters.",
"*** = ###()":
    "Set *** to an instance of class ###.",
"***.***(@@@)": 
    "From *** get the *** function, and call it with parameters self, @@@.",
"***.*** = '***'":
    "From *** get the *** attribute and set it to '***'."
}

# do they want to drill phrases first
PHRASE_FIRST = False
if len(sys.argv) == 2 and sys.argv[1] == "english":
    PHRASE_FIRST = True

# load up the words from the website
for word in urlopen(WORD_URL).readlines():
    WORDS.append(word.strip())

def convert(snippet, phrase):
    class_names = [w.capitalize() for w in
                random.sample(WORDS, snippet.count("###"))]
    other_names = random.sample(WORDS, snippet.count("***"))
    results = []
    param_names = []

    for i in range(0, snippet.count("@@@")): 
        param_count = random.randint(1,3)
        param_names.append(', '.join(random.sample(WORDS, param_count)))

    for sentence in snippet, phrase:
        result = sentence[:]

    # fake class names
    for word in class_names:
        result = result.replace("###", word, 1)

    # fake other names
    for word in other_names:
        result = result.replace("***", word, 1)

    # fake parameter lists
    for word in param_names:
        result = result.replace("@@@", word, 1)

        results.append(result)

    return results

# keep going until they hit CTRL-D
try:
    while True:
        snippets = PHRASES.keys()
        random.shuffle(snippets)

        for snippet in snippets:
            phrase = PHRASES[snippet]
            question, answer = convert(snippet, phrase)
            if PHRASE_FIRST:
                question, answer = answer, question

            print question

            raw_input(">")
            print "ANSWER: %s\n\n" % answer #ERROR : after print - weird

except EOFError:
    print "\nBye"

准确的错误是:

Value Error: Need more than 0 vales to unpack

我才刚刚开始，所以非常感谢解释错误发生的原因以及如何解决它。

Answer 1

除了最后 3 个 for 循环的缩进之外，您的代码是正确的，这应该是嵌套的。

将以下内容缩进 4 个空格，您应该可以开始了:

# fake class names
for word in class_names:
    result = result.replace("###", word, 1)

# fake other names
for word in other_names:
    result = result.replace("***", word, 1)

# fake parameter lists
for word in param_names:
    result = result.replace("@@@", word, 1)