包装长行的首选方法是在括号,括号和括号内使用Python隐含的行继续.通过在括号中包装表达式,可以在多行中分割长行.这些应该优先使用反斜杠来继续行.

反斜杠有时可能仍然合适.例如,long,多个with语句不能使用隐式延续,因此可以接受反斜杠:

with open(‘/path/to/some/file/you/want/to/read’) as file_1, \

open(‘/path/to/some/file/being/written’, ‘w’) as file_2:

file_2.write(file_1.read())

另一个这样的情况是断言语句.

确保适当缩进续行.打破二元运算符的首选位置是运算符之后,而不是它之前.一些例子:

class Rectangle(Blob):

def __init__(self, width, height,

color=’black’, emphasis=None, highlight=0):

if (width == 0 and height == 0 and

color == ‘red’ and emphasis == ‘strong’ or

highlight > 100):

raise ValueError(“sorry, you lose”)

if width == 0 and height == 0 and (color == ‘red’ or

emphasis is None):

raise ValueError(“I don’t think so — values are %s, %s” %

(width, height))

Blob.__init__(self, width, height,

color, emphasis, highlight)