numpy.core.defchararray.index(arr，substring，start = 0，end = None)：查找指定范围内子字符串的最低索引，但如果未找到子字符串，则会引发ValueError。
参数:
arr : array-like or string to be searched.
substring : substring to search for.
start, end: [int, optional] Range to search in.返回: An integer array with the lowest index of found sub-string, raises ValueError if substring is not found.
代码1：
# Python Program illustrating
# numpy.char.index() method
import numpy as np
arr = ['this is geeks for geek']
print ("arr:", arr)
print ("\nindex of 'geeks':", np.char.index(arr, 'geeks'))输出：
arr: ['this is geeks for geek'] index of 'geeks':[8]
代码2：
# Python Program illustrating
# numpy.char.index() method
import numpy as np
arr = ['this is geeks for geek']
print ("\nindex of 'geeks':", np.char.index(arr, 'geeks', start = 2))
print ("\nindex of 'geeks':", np.char.index(arr, 'geeks', start = 10))
print ("\nindex of 'geek':", np.char.index(arr, 'geek', start = 10))输出：
index of 'geeks':[8] ValueError: substring not found index of 'geek':[18]
相关用法
注：本文由纯净天空筛选整理自Mohit Gupta_OMG 大神的英文原创作品 numpy.index() in Python。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。