numpy.core.defchararray.index(arr，substring，start = 0，end = None)：查找指定範圍內子字符串的最低索引，但如果未找到子字符串，則會引發ValueError。
參數:
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.
代碼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'))輸出：
arr: ['this is geeks for geek'] index of 'geeks':[8]
代碼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))輸出：
index of 'geeks':[8] ValueError: substring not found index of 'geek':[18]
相關用法
注：本文由純淨天空篩選整理自Mohit Gupta_OMG 大神的英文原創作品 numpy.index() in Python。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。