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。

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', '')

因为相邻的字符串常量是自动连接的，你可以这样编码:

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

注意没有加号，我在示例的格式后面添加了额外的逗号和空格。

就我个人而言，我不喜欢反斜杠，我记得在某个地方读到过，它的使用实际上是被反对的，而支持这种更明确的形式。记住“显式优于隐式”。

我认为反斜杠不太清楚，也不太有用，因为这实际上是转义换行符。如果需要的话，不能在它后面加上行结束注释。可以通过串接字符串常量来实现:

s = ("this is my really, really, really, really, really, really, " # comments ok
     "really long string that I'd like to shorten.")

我使用谷歌搜索“python行长”，它返回PEP8链接作为第一个结果，但也链接到另一个关于这个主题的StackOverflow帖子:“为什么python PEP-8应该指定79个字符的最大行长?”

另一个好的搜索短语是“python line continuation”。

如果你必须插入一个长字符串文字，并希望flake8关闭，你可以使用它的关闭指令。例如，在一个测试例程中，我定义了一些假的CSV输入。我发现把它分成更多行会非常混乱，所以我决定添加一个# noqa: E501，如下所示:

csv_test_content = """"STATION","DATE","SOURCE","LATITUDE","LONGITUDE","ELEVATION","NAME","REPORT_TYPE","CALL_SIGN","QUALITY_CONTROL","WND","CIG","VIS","TMP","DEW","SLP","AA1","AA2","AY1","AY2","GF1","MW1","REM"
"94733099999","2019-01-03T22:00:00","4","-32.5833333","151.1666666","45.0","SINGLETON STP, AS","FM-12","99999","V020","050,1,N,0010,1","22000,1,9,N","025000,1,9,9","+0260,1","+0210,1","99999,9","24,0000,9,1",,"0,1,02,1","0,1,02,1","01,99,1,99,9,99,9,99999,9,99,9,99,9","01,1","SYN05294733 11/75 10502 10260 20210 60004 70100 333 70000="
"94733099999","2019-01-04T04:00:00","4","-32.5833333","151.1666666","45.0","SINGLETON STP, AS","FM-12","99999","V020","090,1,N,0021,1","22000,1,9,N","025000,1,9,9","+0378,1","+0172,1","99999,9","06,0000,9,1",,"0,1,02,1","0,1,02,1","03,99,1,99,9,99,9,99999,9,99,9,99,9","03,1","SYN04294733 11/75 30904 10378 20172 60001 70300="
"94733099999","2019-01-04T22:00:00","4","-32.5833333","151.1666666","45.0","SINGLETON STP, AS","FM-12","99999","V020","290,1,N,0057,1","99999,9,9,N","020000,1,9,9","+0339,1","+0201,1","99999,9","24,0000,9,1",,"0,1,02,1","0,1,02,1",,"02,1","SYN05294733 11970 02911 10339 20201 60004 70200 333 70000="
"94733099999","2019-01-05T22:00:00","4","-32.5833333","151.1666666","45.0","SINGLETON STP, AS","FM-12","99999","V020","200,1,N,0026,1","99999,9,9,N","000100,1,9,9","+0209,1","+0193,1","99999,9","24,0004,3,1",,"1,1,02,1","1,1,02,1","08,99,1,99,9,99,9,99999,9,99,9,99,9","51,1","SYN05294733 11/01 82005 10209 20193 69944 75111 333 70004="
"94733099999","2019-01-08T04:00:00","4","-32.5833333","151.1666666","45.0","SINGLETON STP, AS","FM-12","99999","V020","070,1,N,0026,1","22000,1,9,N","025000,1,9,9","+0344,1","+0213,1","99999,9","06,0000,9,1",,"2,1,02,1","2,1,02,1","04,99,1,99,9,99,9,99999,9,99,9,99,9","02,1","SYN04294733 11/75 40705 10344 20213 60001 70222="
"""  # noqa: E501

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
>>> 

反斜杠:

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

或者用括号括起来:

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