Python精彩代码片段

用使用类的方式来使用字典

 class DownloadContext(dict):
            __getattr__ = dict.get
            __setattr__ = dict.__setitem__
            __delattr__ = dict.__delitem__
            
# 实例化一个DownloadContext，然后随意的往里面插入属性
ctx = DownloadContext()
ctx.filename = 'abc.txt'
ctx.aaa = 'abc'

不想写try...except...的时候，使用contextlib.suppress

from contextlib import suppress

with suppress(FileNotFoundError):
    os.remove('somefile.tmp')
    
This code is equivalent to:

try:
    os.remove('somefile.tmp')
except FileNotFoundError:
    pass

转换任意对象为可迭代对象

def variadic(x, allowed_types=(str, bytes, dict)):
    return x if isinstance(x, collections.abc.Iterable) and not isinstance(x, allowed_types) else (x,)

随机生成user-agent

def random_user_agent():
    _USER_AGENT_TPL = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/%s Safari/537.36'
    _CHROME_VERSIONS = (
        '90.0.4430.212',
        '90.0.4430.24',
        '90.0.4430.70',
        '90.0.4430.72',
        '90.0.4430.85',
        '90.0.4430.93',
        '91.0.4472.101',
        '91.0.4472.106',
        '91.0.4472.114',
        '91.0.4472.124',
        '91.0.4472.164',
        '91.0.4472.19',
        '91.0.4472.77',
        '92.0.4515.107',
        '92.0.4515.115',
        '92.0.4515.131',
        '92.0.4515.159',
        '92.0.4515.43',
        '93.0.4556.0',
        '93.0.4577.15',
        '93.0.4577.63',
        '93.0.4577.82',
        '94.0.4606.41',
        '94.0.4606.54',
        '94.0.4606.61',
        '94.0.4606.71',
        '94.0.4606.81',
        '94.0.4606.85',
        '95.0.4638.17',
        '95.0.4638.50',
        '95.0.4638.54',
        '95.0.4638.69',
        '95.0.4638.74',
        '96.0.4664.18',
        '96.0.4664.45',
        '96.0.4664.55',
        '96.0.4664.93',
        '97.0.4692.20',
    )
    return _USER_AGENT_TPL % random.choice(_CHROME_VERSIONS)