numpy字符串操作 | rfind()函数

numpy.core.defchararray.find(arr, sub, start=0, end=None)是另一个用于在 numpy 中进行字符串操作的函数。它返回字符串中为 arr 中的每个元素找到子字符串sub 的最高索引。如果 sub 不包含在[start, end]中，则返回 -1。

Parameters:
arr : array_like of str or unicode.
sub : [str or unicode] The substring which to be searched.
start : [ int, optional] The starting location in each string.
end : [ int, optional] The ending location in each string.

Returns : [ndarray] Output array of ints.

代码#1：

# Python program explaining
# numpy.char.rfind() method 
  
# importing numpy as geek
import numpy as geek
  
# input arrays  
in_arr = geek.array(['aAaAaA', 'baA', 'abBABba'])
print ("Input array : ", in_arr) 
  
# output arrays 
out_arr = geek.char.rfind(in_arr, sub ='A')
print ("Output array: ", out_arr) 

输出：

Input array :  ['aAaAaA' 'baA' 'abBABba']
Output array:  [5 2 3]

代码#2：

# Python program explaining
# numpy.char.rfind() method 
  
# importing numpy as geek
import numpy as geek
  
# input arrays  
in_arr = geek.array(['aAaAaA', 'aA', 'abBABba'])
print ("Input array : ", in_arr) 
  
# output arrays 
out_arr = geek.char.rfind(in_arr, sub ='a', start = 3, end = 7)
print ("Output array: ", out_arr) 

输出：

Input array :  ['aAaAaA' 'aA' 'abBABba']
Output array:  [ 4 -1  6]