Python中的 numpy.find()

numpy.core.defchararray.find(arr, substring, start=0, end=None) ：查找指定范围内子字符串的最低索引。

Parameters:
arr : array-like or string to be searched.
substring : substring to search for.
start, end : [int, optional] Range to search in.

Returns : An integer array with the lowest index of found sub-string.

代码#1：

# Python Program illustrating 
# numpy.char.find() method 
import numpy as np 
  
arr = ['vdsdsttetteteAAAa', 'AAAAAAAaattttds', 'AAaaxxxxtt', 'AAaaXDSDdscz']
  
print ("arr : ", arr)
  
print ("\nfind of 'tt'", np.char.find(arr, 'tt'))
print ("find of 'tt'", np.char.find(arr, 'tt', start = 0))
print ("find of 'tt'", np.char.find(arr, 'tt', start = 8))

输出：

arr :  ['vdsdsttetteteAAAa', 'AAAAAAAaattttds', 'AAaaxxxxtt', 'AAaaXDSDdscz']

find of 'tt' [ 5  9  8 -1]
find of 'tt' [ 5  9  8 -1]
find of 'tt' [ 8  9  8 -1]

代码#2：

# Python Program illustrating 
# numpy.char.find() method 
import numpy as np 
  
arr = ['vdsdsttetteteAAAa', 'AAAAAAAaattttds', 'AAaaxxxxtt', 'AAaaXDSDdscz']
  
  
print ("\nfind of 'Aa'", np.char.find(arr, 'Aa'))
print ("find of 'Aa'", np.char.find(arr, 'Aa', start = 8))

输出：

find of 'Aa' [15  6  1  1]
find of 'Aa' [15 -1 -1 -1]