python开发_random

和java中的random()函数一样，在python中也有类似的模块random，即随机数

下面是我做的demo

运行效果：

==========================================

代码部分：

==========================================

 #python random

 import random

 def get_random():
     '''get a random number.
     return Random float x, 0.0 <= x < 1.0'''
     return random.random()

 def get_uniform(a, b):
     '''Return a random floating point number N such that
     a <= N <= b for a <= b and b <= N <= a for b < a.
     The end-point value b may or may not be included in the
     range depending on floating-point rounding in the
     equation a + (b-a) * random().
     '''
     return random.uniform(a, b)

 def get_randrange(n):
     '''return an Integer from 0 to n
     and the number n must be greater than 0
     or n > 0
     '''
     return random.randrange(n)

 def get_randrange_ex(start, stop, step):
     '''返回一个从start开始到stop结束，步长为step的随机数'''
     return random.randrange(start, stop, step)

 def choice(s):
     '''从一个字符串中随机获取一个字符串，传入的参数s是不能为空或者不能为None'''
     if s != '' and s != None:
         return random.choice(s)
     else:
         print('the param is empty or equals None!')

 def shuffle(items):
     '''对一个序列进行洗牌的操作'''
     random.shuffle(items)
     return items

 def sample(items, n):
     '''从一个序列中随机抽出n个数，当然，在这n个数中，可能出现有重复的数'''
     return random.sample(items, n)

 def main():
     r = get_random()
     print('获取一个0.0-1.0之间的随机数：{}'.format(r))
     r = get_uniform(2, 100)
     print('获取一个2.0-100.0之间的随机数：{}'.format(r))
     r = get_randrange(100)
     print('获取一个0-100之间的随机数：{}'.format(r))
     r = get_randrange_ex(3, 100, 25)
     print('获取一个3-100之间的随机数：{}'.format(r))
     tem_str = 'this is a test message!'
     r = choice(tem_str)
     print('从[{}]中随机取出一个字符：{}'.format(tem_str, r))
     tem_items = [1, 2, 3, 4, 5, 6, 7]
     tem_r = tem_items[:]
     shuffle(tem_items)
     print('对序列{}进行洗牌操作：{}'.format(tem_r, tem_items))

     tem_list = sample(tem_r, 3)
     print('从{}中随机抽出3个数：{}'.format(tem_r, tem_list))

 if __name__ == '__main__':
     main()