正如PEP8所建议的那样,在python程序中保持低于80列的规则,对于长字符串,我怎么能遵守这个规则呢?

s = "this is my really, really, really, really, really, really, really long string that I'd like to shorten."

我该如何把它扩展到下面一行呢?

s = "this is my really, really, really, really, really, really" + 
    "really long string that I'd like to shorten."

当前回答

我以前用过textwrap.dedent。这有点麻烦,所以我现在更喜欢行延续,但如果你真的想要块缩进,我认为这很好。

示例代码(其中trim是去掉带有切片的第一个'\n'):

import textwrap as tw
x = """\
       This is a yet another test.
       This is only a test"""
print(tw.dedent(x))

解释:

Dedent根据新行前第一行文本中的空白计算缩进。如果你想调整它,你可以使用re模块轻松地重新实现它。

这种方法有局限性,很长的行可能仍然比你想要的长,在这种情况下,其他方法连接字符串更适合。

其他回答

我觉得你问题中最重要的一个词是“suggest”。

编码标准是很有趣的东西。通常他们提供的指导在编写时有很好的基础(例如,大多数终端无法在一行上显示> 80个字符),但随着时间的推移,它们在功能上变得过时了,但仍然被严格遵守。我猜您在这里需要做的是权衡“破坏”特定建议与代码的可读性和可维护性之间的相对优点。

抱歉,这并不能直接回答你的问题。

我倾向于使用几个这里没有提到的方法来指定大字符串,但这些方法适用于非常特定的场景。YMMV……

Multi-line blobs of text, often with formatted tokens (not quite what you were asking, but still useful): error_message = ''' I generally like to see how my helpful, sometimes multi-line error messages will look against the left border. '''.strip() Grow the variable piece-by-piece through whatever string interpolation method you prefer: var = 'This is the start of a very,' var = f'{var} very long string which could' var = f'{var} contain a ridiculous number' var = f'{var} of words.' Read it from a file. PEP-8 doesn't limit the length of strings in a file; just the lines of your code. :) Use brute-force or your editor to split the string into managaeble lines using newlines, and then remove all newlines. (Similar to the first technique I listed): foo = ''' agreatbigstringthatyoudonotwanttohaveanyne wlinesinbutforsomereasonyouneedtospecifyit verbatimintheactualcodejustlikethis '''.replace('\n', '')

message = f"Variable : child({type(child)}) -> is not of"\
        " type Node."

这个语法适合我。注意第二个语句的缩进,它应该缩进正确。

可用的选项:

反斜杠:"foo" \ "bar" "foo" + " \ "bar" 括号: (“foo”“酒吧”) 带加号的括号:("foo" + "bar") PEP8, E502:括号之间的反斜杠是多余的

避免

避免使用逗号:("foo", "bar")来定义一个元组。


>>> s = "a" \
... "b"
>>> s
'ab'
>>> type(s)
<class 'str'>
>>> s = "a" + \
... "b"
>>> s
'ab'
>>> type(s)
<class 'str'>
>>> s = ("a"
... "b")
>>> type(s)
<class 'str'>
>>> print(s)
ab
>>> s = ("a",
... "b")
>>> type(s)
<class 'tuple'>
>>> s = ("a" + 
... "b")
>>> type(s)
<class 'str'>
>>> print(s)
ab
>>> 

使用\你可以将语句扩展到多行:

s = "this is my really, really, really, really, really, really" + \
"really long string that I'd like to shorten."

应该工作。