python的内置模块random随机模块方法详解以及使用案例（五位数随机验证码的实现）

1、random(self):

Get the next random number in the range [0.0, 1.0)

取0到1直接的随机浮点数

import random
print(random.random())

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

0.3105503800442595

2、randint(self, a, b)

Return random integer in range [a, b], including both end points.

返回a,b之间的随机整数，包括a和b

import random
print(random.randint(5,99))

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

53

3、randrange(self, start, stop=None, step=1, _int=int):

Choose a random item from range(start, stop[, step]).
This fixes the problem with randint() which includes the
endpoint; in Python this is usually not what you want

返回a,b直接的随机整数，不包括b，就是>=a 小于b的范围

import random
print(random.randrange(1,9))

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

3

还可以指定步长

import random
print(random.randrange(1,9,step=2))

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

5

4、choice(self, seq)

Choose a random element from a non-empty sequence   [ˈelɪmənt] 元素  sequence 序列

取一个不是空的序列里面的随机的一个元素

import random
print(random.choice([11,22,33]))

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

22

5、sample(self, population, k)

Chooses k unique random elements from a population sequence or set

选择k个随机元素从序列里面或者是集合里面，给返回的是一个列表

下面这个例子就是从集合里面随机取2个元素

import random
print(random.sample({11,22,"gouguoqi",66},2))

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

['gouguoqi', 11]

6、uniform(self, a, b): 

Get a random number in the range [a, b) or [a, b] depending on rounding

选择a,b之间的随机数的浮点数

import random
print(random.uniform(2,900))

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

621.520221600369

7、shuffle(self, x, random=None)

就是对列表中的元素进行重新洗牌（打乱顺序，没什么卵用）

import random
ret=[11,22,33,44,55]
random.shuffle(ret)
print(ret)

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

[33, 22, 55, 44, 11]

8、制作五位数随机验证码

import random
def v_code():
    ret=""
    for n in range(5):#循环几次
        num=random.randint(0,9)#取0-9之间的随机数字
        alf=chr(random.randint(65,122))#65到122之间的chr就是小写a到z和大写A到Z的范围
        s=str(random.choice([num,alf]))#用choice的方法随机从列表里面取一个元素，转换成str
        ret+=s#每次循环给ret加个s，s是字符串，所以最后ret就是5位数字和字母组合的验证码
    return ret
print(v_code())

C:\python35\python3.exe D:/pyproject/day21模块/random随机模块.py

6s070