Day4 内置函数补充、装饰器

li = [11,22,33,44]def f1(arg):    arg.append(55)#函数默认返回值None，函数参数传递的是引用li = f1(li)

print(li)

内置函数补充：

判断是否被调用

def f1():

pass

print(callable(f1))

ASCII码与数字转换

#数字转换为ASCII码r = chr(65)print(r)#ASCII转换为数字n = ord(‘a‘)print(n)

随机验证码

import randomlist_temp =[]for i in range(10):    r = random.randrange(0,10)    if r == 2 or r == 4 or r == 9:        num = random.randrange(0, 10)        list_temp.append(str(num))    else:        temp = random.randrange(65, 91)        c = chr(temp)        list_temp.append(c)result = "".join(list_temp)print(result)

编译、执行

s = "print(123)"#编译: single(单行), eval（表达式）, exec（编译成和python一样）#将字符串编译成python代码r = compile(s, "<string>", "exec")#exec执行python代码,没有返回值exec(r)

#eval只执行表达式，有返回结果box = "8 * 8"ret = eval(box)print(ret)