python.py

'''=============================插入根目录到path=========================='''
ROOT = os.path.join(os.path.dirname(os.path.realpath(__file__)), "..")
sys.path.insert(0, os.path.join(ROOT))

'''=============================format时间为x天x小时x分=========================='''
import time
import datetime
'{:0>8}'.format(str(datetime.timedelta(seconds=round(time.time() - main_st))))

'''=============================python多进程处理=========================='''
from multiprocessing import Pool

def f(x):
    return x*x

if __name__ == '__main__':
    with Pool(5) as p:
        print(p.map(f, [1, 2, 3]))

'''=============================ignore warnings=========================='''
import warnings
with warnings.catch_warnings():
    warnings.simplefilter("ignore")
    # do some operations that will throw warnings
    
'''=============================read first N lines=========================='''
#  from a file
with open("file_name") as myfile:
    head = [next(myfile) for x in range(N)]

'''=============================dict to object=========================='''
# convert 
class objectview(object):
    def __init__(self, d):
        self.__dict__ = d
      
# dotdict, accessing dict item using dot.key
class dotdict(dict):
    """dot.notation access to dictionary attributes"""
    def __getattr__(self, attr):
        return self.get(attr)
    __setattr__ = dict.__setitem__
    __delattr__ = dict.__delitem__
        
'''=============================conditional decorator=========================='''
# python conditional decorator
class conditional_decorator(object):
    def __init__(self, dec, condition):
        self.decorator = dec
        self.condition = condition

    def __call__(self, func):
        if not self.condition:
            # Return the function unchanged, not decorated.
            return func
        return self.decorator(func)

# @functools.lru_cache(maxsize=256, typed=True)
@conditional_decorator(lambda func: functools.lru_cache(maxsize=256, typed=True)(func), hasattr(functools, 'lru_cache'))
def _compile_pattern(pat):
    return re.compile(pat).match