python-random模块

import random

#返回0-1的浮点数
ret = random.random()
print(ret) 

#返回整型
ret = random.randint(1,3) #[1,3]　　
ret = random.randrange(1,3) #[1,3)
ret = random.choice([1,2,3]) #可迭代对象随机返回，应用于验证码
ret = random.sample([1,2,3,4,5,6],2) #随机返回2个元素
ret = random.uniform(x,y) # 返回x-y的浮点数
ret = random.shuffle([1,2,3,4,5]) #打乱列表次序

random函数应用（生成验证码）：

import random

def yanzheng():
    ret = ""
    for i in range(4):
        num = random.randint(0,9)
        alf = chr(random.choice([(random.randint(65,90)),random.randint(97,122)]))
        s = str(random.choice([num,alf]))
        ret += s
    return ret
if __name__ == '__main__':
    code = yanzheng()
    print(code)