看document
https://
docs.scipy.org/doc/numpy-1.15.1/reference/generated/numpy.random.randint.html
low : int
Lowest (signed) integer to be drawn from the distribution
(unless high=None, in which case this parameter is one above the highest such
integer).
可是為什麼下面範例
np.random.randint(2, size=10)
抽出的值是0跟1?
(unless high=None, in which case this parameter is one above the highest such
integer).
this parameter "2" is one above the highest such integer
的意思是說 抽出的最大值是2-1
這樣理解對嗎？ such integer說的是抽出的integer?

除非你有給high 否則low就是high

high是None的情況下, 你給的low會當成high, 而low預設為0range也是類似的做法