random模块用法

最近生病，学习进度少许拖延，，

import  random
# 随机取0~1之间的小数
print(random.random())
# 随机取2数之间的整数
print(random.randint(10,30))
# 随机取2数之间的整数,结束值不包含在范围内
print(random.randrange(1,3))#如3不会取出
# 随机取列表的一个元素
print(random.choice([2,"xx",{"name":"jia"}]))
# 随机取列表的N个元素
print(random.sample([2,"xx",{"name":"jia"},1,4,5,7,8],3))
# 随机取2数之间的浮点型
print(random.uniform(1,9))

以下是用random写的验证码功能

import sys, time,random
# 这是倒计时
def time_remain(lineTmpla, mins):
    count = 0
    mins = int(mins+1)
    while (count < mins):
        count += 1
        n = mins - count
        time.sleep(1)
        sys.stdout.write("\r" + lineTmpla+ "%3s"%n)
        sys.stdout.flush()
        # if n:
        #     print("\r" + lineTmpla+ str(n))
        if not n:
            return '\ncompleted'

# 验证码功能
def yanzhengma(q = 4):
    a= ""
    for i in range(q):
        num = random.randint(0,9)
        alf = chr(random.randint(65,90))
        alf_2 = chr(random.randint(97, 122))
        s = str(random.choice([num,alf,alf_2]))
        a += s
    return a

if __name__ == '__main__':
    flg = 5
    n = input("需要几位验证码：")
    s = yanzhengma(int(n))
    print(s)
    flg_1 =True
    while flg_1:
        if flg == 0:
            time_remain("请等待：", 4)
            flg = 5
        while flg:
            y = input("\n输入验证码：")
            if y == s:
                print("通过")
                flg_1 =False
                break
            else:
                print("还剩%s次"%(flg-1))
                flg -= 1