python - randrange() 的空范围 (1,1,0)

Question

我试图使用 while 循环将列表拆分为训练数据和测试数据，但在运行一两次迭代后，立即弹出 randrange() 错误。无法理解出了什么问题。提取的 csv 文件有 767 行数据。下面是代码:

dataset = list(csv.reader(open("Data\diabetes.csv", 'r'), delimiter = ","))

trainSet = []
trainSize = int(0.67* len(dataset))
while len(trainSet) < trainSize:
      x = len(dataset)
      index = random.randint(1, x-1)
      trainSet.append(dataset[index])
      dataset = dataset.pop(index)

错误如下:

Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
  File "C:\Users\Vikash Patel\AppData\Local\Programs\Python\Python38\lib\random.py", line 248, in randint
   return self.randrange(a, b+1)
  File "C:\Users\Vikash Patel\AppData\Local\Programs\Python\Python38\lib\random.py", line 226, in randrange
   raise ValueError("empty range for randrange() (%d, %d, %d)" % (istart, istop, width))

ValueError:randrange() 的范围为空 (1, 1, 0)

Answer 1

ValueError:empty range for randrange() (1, 1, 0) 当您尝试调用 random.randint(1, 0)

时发生

发生这种情况是因为当您希望数据集具有元素弹出。然后，当循环下次迭代时，x = len(dataset) 设置 x = 1，并且行 index = random.randint(1, x-1)调用 random.randint(1, 0)。

试试这个:

import random

dataset = [10,11,12,13,14,15]

trainSet = []
trainSize = int(0.67* len(dataset))
while len(trainSet) < trainSize:
    x = len(dataset)
    index = random.randint(1, x-1)
    trainSet.append(dataset[index])

    # this changes the size of the dataset
    dataset.pop(index)

输出:

> trainSet
[13, 12, 15, 14]