如何格式化符合PEP8的python断言语句？

Question

如何格式化符合PEP8的长断言语句？请忽略我的例子的人为性质.

def afunc(some_param_name):
    assert isinstance(some_param_name, SomeClassName), 'some_param_name must be an instance of SomeClassName, silly goose!'

无法将其包装在括号中,因为它会更改assert语句的行为,因为它是关键字,而不是内置函数.

Answer 1

重要的是要记住,PEP8只是一个指导原则,甚至指出有时应该打破规则.

但最重要的是:知道何时不一致 - 有时风格指南不适用.

考虑到这一点,我可能会用旧样式行继续写这个:

def afunc(some_param_name):
    assert isinstance(some_param_name, SomeClassName), \ 
           'some_param_name must be an instance of SomeClassName, silly goose!'

如果这不适合你(或你的短信),你可以随时做:

def afunc(some_param_name):
    assert isinstance(some_param_name, SomeClassName), ( 
           'some_param_name must be an instance of SomeClassName, silly goose!')

甚至:

def afunc(some_param_name):
    assert isinstance(some_param_name, SomeClassName), ( 
           'some_param_name must be an instance of SomeClassName, '
           'silly goose!')

Answer 2

ERR_MESSAGE_01 = '''
Some really long error message
'''

assert condition(a,b), ERR_MESSAGE_01

我是怎么做的......而且我觉得这很合适..

Answer 3

值得注意的是，可以用括号括起来，只是不是你想的那样。

assert isinstance(some_param_name, 
                  SomeClassName), ('some_param_name must be an instance of '
                                   'SomeClassName, silly goose!')

然而，我不会认为它特别可读。在某些情况下，这可能是正确的选择。