Python 多行返回语句
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Return statement on multiple lines
提问by Vox
Have scoured the interwebs trying to figure this out but with no luck. As far as I know you usually only have one return statement however my problem is that I need to have line breaks in my return statement in order for the testing to return 'true'. What I've tried is throwing up errors, probably just a rookie mistake. My current function with no attempts to make a line break is below.
已经搜索了互联网，试图解决这个问题，但没有运气。据我所知，您通常只有一个 return 语句，但是我的问题是我的 return 语句中需要换行，以便测试返回“true”。我试过的是抛出错误，可能只是一个新手错误。我当前没有尝试换行的功能如下。
def game(word, con):
return (word + str('!')
word + str(',') + word + str(phrase1)
Are new line breaks (\n) supposed to work in return statements? It's not in my testing.
换行符 (\n) 是否应该在 return 语句中工作？它不在我的测试中。
采纳答案by scott_fakename
In python, an open paren causes subsequent lines to be considered a part of the same line until a close paren.
在 python 中，打开括号会导致后续行被视为同一行的一部分，直到关闭括号。
So you can do:
所以你可以这样做：
def game(word, con):
return (word + str('!') +
word + str(',') +
word + str(phrase1))
But I wouldn't recommend that in this particular case. I mention it since it's syntactically valid and you might use it elsewhere.
但在这种特殊情况下，我不建议这样做。我提到它是因为它在语法上是有效的，你可以在其他地方使用它。
Another thing you can do is use the backslash:
您可以做的另一件事是使用反斜杠：
def game(word, con):
return word + '!' + \
word + ',' + \
word + str(phrase)
# Removed the redundant str('!'), since '!' is a string literal we don't need to convert it
Or, in this particular case, my advice would be to use a formatted string.
或者，在这种特殊情况下，我的建议是使用格式化的字符串。
def game(word, con):
return "{word}!{word},{word}{phrase1}".format(
word=word, phrase1=phrase1")
That looks like it's functionally equivalent to what you're doing in yours but I can't really know. The latter is what I'd do in this case though.
看起来它在功能上等同于你正在做的事情，但我真的不知道。后者是我在这种情况下会做的。
If you want a line break in the STRING, then you can use "\n" as a string literal wherever you need it.
如果您想在 STRING 中换行，那么您可以在任何需要的地方使用“\n”作为字符串文字。
def break_line():
return "line\nbreak"
回答by TerryA
You can split up a line in a return statement, but you have forgotten a parenthesis at the end and that you also need to separate it with another operator (in this case, a +)
您可以在 return 语句中拆分一行，但您忘记了末尾的括号，并且您还需要将其与另一个运算符分隔（在本例中为 a +）
Change:
改变：
def game(word, con):
return (word + str('!')
word + str(',') + word + str(phrase1)
To:
到：
def game(word, con):
return (word + str('!') + # <--- plus sign
word + str(',') + word + str(phrase1))
# ^ Note the extra parenthesis
Note that calling str()on '!'and ','is pointless. They are already strings.
请注意，调用str()上'!'和','是没有意义的。它们已经是字符串。
回答by James Polley
First - you're using str() to convert several strings to strings. This is not neccessary.
首先 - 您使用 str() 将多个字符串转换为字符串。这不是必需的。
Second - there's nothing in your code that would insert a newline in the string you're building. Just having a newline in the middle of the string doesn't add a newline, you need to do that explicitly.
其次 - 您的代码中没有任何内容可以在您正在构建的字符串中插入换行符。只是在字符串中间有一个换行符不会添加换行符，您需要明确地这样做。
I think that what you're trying to do would be something like this:
我认为你想要做的是这样的：
def game(word, con):
return (word + '!' + '\n' +
word + ',' + word + str(phrase1))
I'm leaving in the call to str(phrase1)since I don't know what phrase1 is - if it's already a string, or has a this shouldn't be needed..__str__()method
我要离开的调用str(phrase1)，因为我不知道什么是phrase1 -如果它已经是一个字符串，或有一个这不应该是必要的。.__str__()方法，
I'm assuming that the string you're trying to build spans the two lines, so I've added the missing parenthesis at the end.
我假设您尝试构建的字符串跨越两行，因此我在末尾添加了缺少的括号。
