Question

在执行ZED A. SHAW的“学习Python困难之路”一书中练习41的示例片段时出现错误。。

我收到的错误：回溯（最近一次调用最后一次）：

File "oop_test.py", line 75, in <module>
question, answer = convert(snippet, phrase)
File "oop_test.py", line 48, in convert
result = sentence.copy()
AttributeError: 'str' object has no attribute 'copy'

摘录：

import random
from urllib.request 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 *** params.",
    "class %%%(object):\n\tdef ***(self, @@@)":
      "class %%% has-a function *** that takes self and @@@ params.",
    "*** = %%%()":
      "Set *** to an instance of class %%%.",
    "***.***(@@@)":
      "From *** get the *** function, call it with params self, @@@.",
    "***.*** = '***'":
      "From *** get the *** attribute and set it to '***'."
}

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

# load up the words from the website
for word in urlopen(WORD_URL).readlines():
    WORDS.append(str(word.strip(), encoding="utf-8"))


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:
        # this is how you duplicate a list or string
        result = sentence.copy()

        # 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 = list(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)

            input("> ")
            print(f"ANSWER:  {answer}\n\n")
except EOFError:
    print("\nBye")

看起来它不被解释为字典或列表？我真的不明白为什么复制方法不起作用？我通过删除第48行的.copy并使用'result = sentence'解决了'但是我想这没有得到妥善修复，并且有一个原因作者使用.copy？

Answer 1

偶然发现了这一点，在我的本书版本中，该行是

结果=句子[：]

希望有所帮助

学习Python艰难的方式Ex。 41 - 学会说话面向对象

1 个答案: