python中装饰器、内置函数、json的详解

def run():
    time.sleep(1)print('run....')

def run():
    start_time = time.time()
    time.sleep(1)print('run....')
    end_time = time.time()print('run time', end_time - start_time)

def timer(func):      #计算时间start_time = time.time()
    func()
    end_time = time.time()print('run time', end_time - start_time)    
def run():           #业务代码time.sleep(1)print('run....')
timer(run)

def timer(func):      #计算时间def deco(*args, **kwargs):   #可以传参start_time = time.time()
        func(*args, **kwargs)    #函数调用end_time = time.time()print('run time', end_time - start_time)return deco               #return 函数名，函数即变量def run():           #业务代码time.sleep(1)print('run....')

run = timer(run)       #run相当于decorun()                  #run调用相当于deco()

 timer(func):       deco(*args, **kwargs):   start_time =*args, **kwargs)    end_time =(, end_time - deco               @timer                run():           time.sleep(1()
run()

def run():
    start_time = time.time()
    time.sleep(1)print('run....')
    end_time = time.time()print('run time', end_time - start_time)

print(all([1, 2, 3, 0, 11, -1]))   #判断可迭代对象里面的值是否都为真，有一个为假即为False，非空即真非0即真print(any([0, 1, 2]))              #判断可迭代对象里面的值是否有一个为真，即为Trueprint(bin(10))                    #将十进制转换为二进制print(bool('sdf'))                   #将一个对象转换为布尔类型func = ''print(callable(func))             #判断传入的对象是否可调用，func为变量不可调用，即返回Falsedef adf():passprint(callable(adf))             #判断传入的对象是否可调用，adf为方法即可调用，即返回Trueprint(chr(98))               #打印数字对应的ASCII码，98=bprint(ord('a'))              #打印字符串对应的ASCII码， a=97print(dict(a=1, b=2))        #转换成字典，{'b': 2, 'a': 1}#print(eval('[a=1]'))print(exec('def a():pass'))   #执行python代码，只能执行简单的，定义数据类型和运算def func(num):
    name = '88'print(locals())print(globals())return numprint(list(filter(func, [0, 1, 2, 3, 4])))  #在python3里面这么用是没问题filter(func, [1, 2, 3, 4])                  #根据前面的函数处理逻辑，依次处理后面可迭代对象里面的每个元素，返回true保存print(list(map(func, [0, 1, 2, 3, 4])))      #根据前面的函数处理逻辑，依次处理后面可迭代对象里面的每个元素，保存前面函数返回的所有结果 </span>print(globals())                             #返回程序内所有的变量，返回的是一个字典,函数里面的局部变量不会返回print(locals())                              #返回局部变量print(hex(111))                              #数字转成16进制print(max(111, 12, 13, 14, 16, 19))           #取最大值print(oct(111))                              #把数字转换成8进制print(round(11.1198, 2))                      #取几位小数,会四舍五入print(sorted([2, 31, 34, 6, 1, 23, 4], reverse=False))#排序

dic={1:2,3:4,5:6,7:8}print(sorted(dic.items()))                         #按照字典的key排序,[(1, 2), (3, 4), (5, 6), (7, 8)]print(sorted(dic.items(), key=lambda x:x[1]))     #按照字典的value排序import time                          #导入一个模块import sysprint(sys.path)   #查看系统环境变量有哪些目录sys.path.append(r'E:\python_workspace\base-code')  #将base-code下的代码添加到环境变量，允许python xxx.py就不报错from day4.day5_test import hhh
hhh()                                            #直接右键允许不报错，使用python  model2.py允许时报错，找不到day4模块No module named 'day4'

import randomprint(random.randint(1, 20))             #在1-19之间随机生成一个整数，随机print(random.choice('abs123'))           #随机取一个元素，随机可迭代对象：字符串、字典、list、元组print(random.sample('abcdfgrtw12', 3))   #随机取几个元素，3是长度，['2', 'a', 'b']，返回结果是list类型print(random.uniform(1, 9))              #随机浮点数，随机取1-9之间的浮点数，可指定范围，5.8791750348305625print(random.random())                    #随机0-1的浮点数，0.9465901444615425random.shuffle([1, 2, 3, 4, 5, 6])  #随机打乱list的值，只能是list

{"car":{"price":1100,"color":"red"},"mac":{"price":7999,"color":"black"},"abc":{"price":122,"color":"green"}}

import json
with open('a.json') as fp:
    shop_dic = json.load(fp)  #从a.json文件内读取数据，返回结果为字典：{'abc': {'price': 122, 'color': 'green'}, 'mac': {'price': 7999, 'color': 'black'}, 'car': {'price': 1100, 'color': 'red'}}print(shop_dic)

s_json = '{"name":"niuniu","age":20,"status":true}'print(json.loads(s_json))         #将json串转换为字典：{'age': 20, 'status': True, 'name': 'niuniu'}

import json
with open('a.json', 'a+') as fp:
    dic = {'name': 'niuniu', 'age': 18}
    fp.seek(0)
    fp.truncate()
    json.dump(dic, fp)    #将字典转换为json串写入文件

{"age": 18, "name": "niuniu"}

import json
dic = {'name': 'niuniu', 'age': 18}print(json.dumps(dic))           #将字典转换为json串：{"name": "niuniu", "age"