概述：
可以從一個int數字或1維array裡隨機選取內容，並將選取結果放入n維array中返回。

說明：

numpy.random.choice(a, size=None, replace=True, p=None)

a : 1-D array-like or int
    If an ndarray, a random sample is generated from its elements. 
    If an int, the random sample is generated as if a was np.arange(n)

size : int or
 
 tuple of ints, optional 

replace : boolean, optional
    Whether the sample is with or without replacement

p : 1-D array-like, optional
    The probabilities associated with each entry in a. If not given the sample assumes a uniform distribution over all entries in a.

示例程式碼

>>> np.random.choice(5
 
, 3)
array([0, 3, 4])

>>> np.random.choice(5, 3, p=[0.1, 0, 0.3, 0.6, 0])
array([3, 3, 0])

>>> np.random.choice(5, 3, replace=False)
array([3,1,0])

>>> np.random.choice(5, 3, replace=False, p=[0.1, 0, 0.3, 0.6, 0])
array([2, 3, 0])

>>> aa_milne_arr = ['pooh', 'rabbit', 'piglet'
 
, 'Christopher']

>>> np.random.choice(aa_milne_arr, 5, p=[0.5, 0.1, 0.1, 0.3])
array(['pooh', 'pooh', 'pooh', 'Christopher', 'piglet'],