创建长的多行字符串的Pythonic方法 [英] Pythonic way to create a long multi-line string

问题描述

我的查询时间很长.我想在Python中将其拆分为几行.用JavaScript做到这一点的一种方法是使用几个句子，然后用+运算符将它们连接起来(我知道，这可能不是最有效的方法，但是我并不真正在意此阶段的性能，只是代码可读性).示例:

I have a very long query. I would like to split it in several lines in Python. A way to do it in JavaScript would be using several sentences and joining them with a + operator (I know, maybe it's not the most efficient way to do it, but I'm not really concerned about performance in this stage, just code readability). Example:

var long_string = 'some text not important. just garbage to' +
                  'illustrate my example';

我尝试在Python中做类似的事情，但是没有用，所以我使用\来拆分长字符串.但是，我不确定这是否是唯一/最佳/最佳的方法.看起来很尴尬. 实际代码:

I tried doing something similar in Python, but it didn't work, so I used \ to split the long string. However, I'm not sure if this is the only/best/pythonicest way of doing it. It looks awkward. Actual code:

query = 'SELECT action.descr as "action", '\
    'role.id as role_id,'\
    'role.descr as role'\
    'FROM '\
    'public.role_action_def,'\
    'public.role,'\
    'public.record_def, '\
    'public.action'\
    'WHERE role.id = role_action_def.role_id AND'\
    'record_def.id = role_action_def.def_id AND'\
    'action.id = role_action_def.action_id AND'\
    'role_action_def.account_id = ' + account_id + ' AND'\
    'record_def.account_id=' + account_id + ' AND'\
    'def_id=' + def_id

推荐答案

您是否在谈论多行字符串?很容易，使用三引号将其开始和结束.

Are you talking about multi-line strings? Easy, use triple quotes to start and end them.

s = """ this is a very
        long string if I had the
        energy to type more and more ..."""

您也可以使用单引号(当然在开始和结束时使用3个单引号)，并将生成的字符串s与其他任何字符串一样对待.

You can use single quotes too (3 of them of course at start and end) and treat the resulting string s just like any other string.

注意:与任何字符串一样，引号和结尾引号之间的任何内容都将成为字符串的一部分，因此本示例中有一个前导空格(如@ root45所指出).此字符串还将包含空格和换行符.

NOTE: Just as with any string, anything between the starting and ending quotes becomes part of the string, so this example has a leading blank (as pointed out by @root45). This string will also contain both blanks and newlines.

即:

' this is a very\n        long string if I had the\n        energy to type more and more ...'

最后，还可以像这样在Python中构造长行:

Finally, one can also construct long lines in Python like this:

 s = ("this is a very"
      "long string too"
      "for sure ..."
     )

将不包括任何多余的空格或换行符(这是一个有意的示例，显示了跳过空格的结果将导致什么):

which will not include any extra blanks or newlines (this is a deliberate example showing what the effect of skipping blanks will result in):

'this is a verylong string toofor sure ...'

不需要逗号，只需将要连接的字符串放在一对括号中，并确保考虑到任何需要的空格和换行符.

No commas required, simply place the strings to be joined together into a pair of parenthesis and be sure to account for any needed blanks and newlines.

这篇关于创建长的多行字符串的Pythonic方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！