merge dict

def merge(defaults, override):

    r = {}

    for k, v in defaults.items():

        if k in override:

            if isinstance(v, dict):

                r[k] = merge(v, override[k])

            else:

                r[k] = override[k]

        else:

            r[k] = v

    return r

赋值判断

k = v1 if [condition] else v2

构建字典

a = ('a', 'b', 'c')

c = (1, 2 ,3)

r = {}

for k, v in zip(a, c):

    r[k] = v

使字典支持点查找

class Dict(dict):

    def __init__(self, names=(), values=(), **kw):

        super(Dict, self).__init__(**kw)

        for k, v in zip(names, values):

            self[k] = v

    def __getattr__(self, key):

         try:

            return self[key]

         except KeyError:

            raise AttributeError(r"'Dict' object has no attribute '%s'" % key)

    def __setattr__(self, key, value):

        self[key] = value

def toDict(d):

    D = Dict()

    for k, v in d.items():

        D[k] = toDict(v) if isinstance(v, dict) else v

    return D

判断是否为函数

callable(fn)

获取其他模块变量/函数

mod = __import__(module_name, globals(), locals())

for attr in dir(mod):

    fn = getattr(mod, attr)

    if callable(fn):

        ......

参数类型判断

params = inspect.signature(fn).parameters

for name, param in params.items():

    if param.kind == inspect.Parameter.KEYWORD_ONLY:

    .....

POSITIONAL_ONLY        位置参数

POSITIONAL_OR_KEYWORD  位置参数或关键字参数

KEYWORD_ONLY           关键字参数

VAR_POSITIONAL         可变位置参数 *args

VAR_KEYWORD            可变关键字参数 **kw

创建进程

import multiprocessing, os, time

def whoami(name):

	print("I'm %s, in process %s" % (name, os.getpid()))

def loopy(name):

	whoami(name)

	start = 1

	stop = 1000000

	for num in range(start, stop):

		print("\tNumber %s of %s. Honk!" % (num, stop))

		time.sleep(1)

if __name__ == '__main__':

	whoami('main')

	#创建进程

	p = multiprocessing.Process(target=loopy, args=('loopy', ))

	p.start()

	time.sleep(5)

	#终止对应进程

	p.terminate()

打开文件

file = open('demo.py', 'r', encoding='UTF-8')

try:

    for line in file:

        print(line, end='')

except:

    print('讀取檔案發生錯誤')

finally:

    file.close()

//简化

with open('demo.py', 'r', encoding='UTF-8') as file:

    for line in file:

        print(line, end='')