python - 在 "in"之后有 2 个变量的循环

Question

我对下面的说法感到困惑

for sentence in snippet, phrase. 

为什么“in”后面有两个项目

完整代码

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

Answer 1

这只是一个两次循环。在第一次迭代中，sentence 设置为 snippet。在第二次迭代中，sentence 设置为 phrase。

这是一个简单的例子:

>>> for x in "a", "b":
...     print(x)
...
a
b
>>>