Exercise 41: Learning To Speak Object Oriented

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):
	def __init__(self, ***)" : "class ### has-a __init__ that takes self and *** parameters.",
    "class ###(object):
	def ***(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

" % answer
except EOFError:
    print "
Bye"

后半部分没看懂要表达啥意思，错误在于convert 那里返回的一个list, 却有两个值。

日后再看吧。