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知识问答

如何使用Pandas创建随机整数的DataFrame？

问题：如何使用Pandas创建随机整数的DataFrame？

我知道如果我使用randn，

import pandas as pd
import numpy as np
df = pd.DataFrame(np.random.randn(100, 4), columns=list('ABCD'))

给了我我想要的东西，但是带有正态分布的元素。但是，如果我只想要随机整数怎么办？

randint通过提供范围来工作，但不能像提供数组那样randn工作。那么我该如何使用某个范围之间的随机整数呢？

点击查看英文原文

I know that if I use randn,

import pandas as pd
import numpy as np
df = pd.DataFrame(np.random.randn(100, 4), columns=list('ABCD'))

gives me what I am looking for, but with elements from a normal distribution. But what if I just wanted random integers?

randint works by providing a range, but not an array like randn does. So how do I do this with random integers between some range?

回答 0

numpy.random.randint接受第三个参数（size），您可以在其中指定输出数组的大小。您可以使用它来创建DataFrame–

df = pd.DataFrame(np.random.randint(0,100,size=(100, 4)), columns=list('ABCD'))

此处- np.random.randint(0,100,size=(100, 4))创建一个大小为的输出数组，(100,4)其中的随机整数元素在之间[0,100)。

演示-

import numpy as np
import pandas as pd
df = pd.DataFrame(np.random.randint(0,100,size=(100, 4)), columns=list('ABCD'))

生成：

     A   B   C   D
0   45  88  44  92
1   62  34   2  86
2   85  65  11  31
3   74  43  42  56
4   90  38  34  93
5    0  94  45  10
6   58  23  23  60
..  ..  ..  ..  ..
点击查看英文原文

numpy.random.randint accepts a third argument (size) , in which you can specify the size of the output array. You can use this to create your DataFrame –

df = pd.DataFrame(np.random.randint(0,100,size=(100, 4)), columns=list('ABCD'))

Here – np.random.randint(0,100,size=(100, 4)) – creates an output array of size (100,4) with random integer elements between [0,100) .

Demo –

import numpy as np
import pandas as pd
df = pd.DataFrame(np.random.randint(0,100,size=(100, 4)), columns=list('ABCD'))

which produces:

     A   B   C   D
0   45  88  44  92
1   62  34   2  86
2   85  65  11  31
3   74  43  42  56
4   90  38  34  93
5    0  94  45  10
6   58  23  23  60
..  ..  ..  ..  ..

回答 1

如今，建议使用NumPy创建随机整数的方法是使用numpy.random.Generator.integers。（文件）

import numpy as np
import pandas as pd

rng = np.random.default_rng()
df = pd.DataFrame(rng.integers(0, 100, size=(100, 4)), columns=list('ABCD'))
df
----------------------
      A    B    C    D
 0   58   96   82   24
 1   21    3   35   36
 2   67   79   22   78
 3   81   65   77   94
 4   73    6   70   96
... ...  ...  ...  ...
95   76   32   28   51
96   33   68   54   77
97   76   43   57   43
98   34   64   12   57
99   81   77   32   50
100 rows × 4 columns
点击查看英文原文

The recommended way to create random integers with NumPy these days is to use numpy.random.Generator.integers. (documentation)

import numpy as np
import pandas as pd

rng = np.random.default_rng()
df = pd.DataFrame(rng.integers(0, 100, size=(100, 4)), columns=list('ABCD'))
df
----------------------
      A    B    C    D
 0   58   96   82   24
 1   21    3   35   36
 2   67   79   22   78
 3   81   65   77   94
 4   73    6   70   96
... ...  ...  ...  ...
95   76   32   28   51
96   33   68   54   77
97   76   43   57   43
98   34   64   12   57
99   81   77   32   50
100 rows × 4 columns