作为Python中长字符串的一般方法，可以使用三引号、拆分和连接：

_str = ' '.join('''Lorem ipsum dolor sit amet, consectetur adipiscing
        elit, sed do eiusmod tempor incididunt ut labore et dolore
        magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation
        ullamco laboris nisi ut aliquip ex ea commodo.'''.split())

输出：

'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo.'

关于OP关于SQL查询的问题，下面的答案忽略了这种构建SQL查询方法的正确性，只关注于以可读和美观的方式构建长字符串，而不需要额外的导入。它也忽略了这带来的计算负载。

使用三重引号，我们构建了一个长且可读的字符串，然后使用split（）将其分解为一个列表，从而剥离空白，然后使用“”.jjoin（）将它连接起来。最后，我们使用format（）命令插入变量：

account_id = 123
def_id = 321

_str = '''
    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 = {}
    AND record_def.account_id = {}
    AND def_id = {}
    '''

query = ' '.join(_str.split()).format(account_id, account_id, def_id)

生产：

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 = 123 AND record_def.account_id=123 AND def_id=321

这种方法不符合PEP8，但我发现它有时很有用。

请注意，format（）函数使用了原始字符串中的大括号。

例如：

sql = ("select field1, field2, field3, field4 "
       "from table "
       "where condition1={} "
       "and condition2={}").format(1, 2)

Output: 'select field1, field2, field3, field4 from table
         where condition1=1 and condition2=2'

如果条件的值应该是字符串，可以这样做：

sql = ("select field1, field2, field3, field4 "
       "from table "
       "where condition1='{0}' "
       "and condition2='{1}'").format('2016-10-12', '2017-10-12')

Output: "select field1, field2, field3, field4 from table where
         condition1='2016-10-12' and condition2='2017-10-12'"

我喜欢这种方法，因为它有阅读的特权。在我们有长串的情况下，没有办法！根据您所处的缩进级别，每行仍限于80个字符。。。好没必要说别的

在我看来，Python风格指南仍然非常模糊。我采用了埃罗·奥尔顿的方法，因为它有利于阅读和常识。我明白，风格指南应该帮助我们，而不是让我们的生活一团糟。

class ClassName():
    def method_name():
        if condition_0:
            if condition_1:
                if condition_2:
                    some_variable_0 =\
"""
some_js_func_call(
    undefined,
    {
        'some_attr_0': 'value_0',
        'some_attr_1': 'value_1',
        'some_attr_2': '""" + some_variable_1 + """'
    },
    undefined,
    undefined,
    true
)
"""

结合以下观点：

Levon或Jesse、Faheel和ddrscott

根据我的格式建议，您可以将查询写成：

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
         )

 vars = (account_id, account_id, def_id)     # A tuple of the query variables
 cursor.execute(query, vars)                 # Using Python's sqlite3 module

或类似：

vars = []
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 = '
                 vars.append(account_id) or '?'
             ' AND'
             ' record_def.account_id = '
                 vars.append(account_id) or '?'
             ' AND'
             ' def_id = '
                 vars.append(def_id) or '?'
         )

 cursor.execute(query, tuple(vars))  # Using Python's sqlite3 module

与“IN”和“vars.extend（options）”或“n_options（len（option））”一起使用可能很有趣，其中：

def n_options(count):
    return '(' + ','.join(count*'?') + ')'

或者从darkcaline那里得到的提示是，您可能仍然会在使用前导空格和分隔符以及命名占位符时出错：

SPACE_SEP = ' '
COMMA_SEP = ', '
AND_SEP   = ' AND '

query = SPACE_SEP.join((
    'SELECT',
        COMMA_SEP.join((
        'action.descr as "action"',
        'role.id as role_id',
        'role.descr as role',
        )),
    'FROM',
        COMMA_SEP.join((
        'public.role_action_def',
        'public.role',
        'public.record_def',
        'public.action',
        )),
    'WHERE',
        AND_SEP.join((
        'role.id = role_action_def.role_id',
        'record_def.id = role_action_def.def_id',
        'action.id = role_action_def.action_id',
        'role_action_def.account_id = :account_id',
        'record_def.account_id = :account_id',
        'def_id = :def_id',
        )),
    ))

vars = {'account_id':account_id,'def_id':def_id}  # A dictionary of the query variables
cursor.execute(query, vars)                       # Using Python's sqlite3 module

请参阅Cursor.execute-function的文档。

“这是[最Python]的方式！”-。。。

PEP 8风格指南建议使用括号：

包装长行的首选方式是在括号、括号和大括号内使用Python的隐含行延续。通过将表达式括在括号中，可以在多行上打断长行。应优先使用这些字符，而不是使用反斜杠作为换行符。

例子：

long_string = (
    "This is a lengthy string that takes up a lot of space. I am going to "
    "keep on typing words to fill up more and more space to show how you can "
    "split the string across multiple lines."
)

“la”Scala方式（但我认为这是OP要求的最具Python风格的方式）：

description = """
            | The intention of this module is to provide a method to
            | pass meta information in markdown_ header files for
            | using it in jinja_ templates.
            |
            | Also, to provide a method to use markdown files as jinja
            | templates. Maybe you prefer to see the code than
            | to install it.""".replace('\n            | \n','\n').replace('            | ',' ')

如果您希望最后的str没有跳转行，只需将\n放在第二个替换的第一个参数的开头：

.replace('\n            | ',' ')`.

注意：“…templates.”和“另外，…”之间的白线需要在|后面加一个空格。