Python-Numpy随机数

一.先来说说Python基本的随机数生成方式

随机整数:

import random
#生成0-99之间随机整数
 print(random.randint(0,99))

随机浮点数:

>>> random.random()
0.5750683162290557
>>> import random
>>> random.uniform(1,10)
1.537218811475957

随机字符:

>>> random.choice('abcdefg$%^&*')
'$'
>>> random.choice('abcdefg$%^&*')
'c'

随机字符串:

>>> random.choice(['apple','peach','banana'])
'banana'

二.介绍三种Numpy生成随机数的方法:

1) rand(d0,d1…dn) 根据d0-dn创建随机数数组,浮点数,[0,1),均匀分布

>>> import numpy as np 
>>> a = np.random.rand(3,4,5)
>>> a
array([[[ 0.82052522,  0.39772757,  0.10702767,  0.8500243 ,  0.0990338 ],
        [ 0.41688268,  0.81852505,  0.37949649,  0.30477787,  0.89358199],
        [ 0.29684884,  0.34452373,  0.80421074,  0.40758698,  0.33536057],
        [ 0.73658926,  0.97701813,  0.57473218,  0.32008441,  0.3855367 ]],

       [[ 0.94558899,  0.38385689,  0.86562463,  0.88437479,  0.65539631],
        [ 0.33358347,  0.75279117,  0.20435261,  0.47775278,  0.26806775],
        [ 0.76751492,  0.39889982,  0.55444728,  0.1457183 ,  0.16721214],
        [ 0.96924537,  0.96858455,  0.38874238,  0.68661647,  0.42201225]],

       [[ 0.14854302,  0.9057184 ,  0.32156218,  0.42248953,  0.51643453],
        [ 0.67239167,  0.70776545,  0.13228446,  0.48603424,  0.57457654],
        [ 0.92464257,  0.89040427,  0.54697102,  0.91909625,  0.64871797],
        [ 0.05623798,  0.90024524,  0.2178354 ,  0.02516971,  0.08885865]]])

2) randn(d0,d1…dn) 根据d0-dn创建随机数数组,标准正太分布

>>> sn = np.random.randn(3,4,5)
>>> sn
array([[[ 0.86337373, -1.28532967,  2.22071546,  0.57320661,  0.20942383],
        [-0.45122977,  1.41654004,  0.40633233, -1.03517127, -1.00214081],
        [-1.33099737, -0.10849854, -0.10623566, -1.40064714,  0.56515491],
        [-1.95891391,  1.26105515,  1.84718306, -0.59877648,  0.14339642]],

       [[-1.6822221 , -0.73728456, -0.61499899, -0.62996666,  0.07878297],
        [-0.01023083, -1.13038369, -1.39895922, -0.53454577,  1.54093765],
        [-0.57146229, -0.42142275, -1.10270702, -0.7692162 , -1.17711295],
        [-0.19241645, -1.29446225,  0.9771069 , -2.82338869, -0.26035278]],

       [[-0.25134972,  1.82536516, -0.28314402, -0.74347928, -0.05876521],
        [-0.16721582,  0.93229841, -0.30961706,  0.50778018, -0.54840238],
        [-0.72032043,  0.1800224 ,  1.18602988, -1.42246267, -0.30880924],
        [ 0.33634607,  1.7428904 ,  0.15975399,  0.04358346,  0.74270667]]])
>>> 

3) randint(low,[,high,shape]) 根据shape创建随机整数或整数数组,范围是 [low,high)

>>> b =  np.random.randint(100,200,(3,4))
>>> b
array([[162, 101, 114, 108],
       [133, 191, 150, 102],
       [153, 150, 163, 176]])