使用Python的index()方法返回字串中子字串在指定範圍內出現的最低索引
使用Python NumPy中的numpy.char.index()方法返回字串中子字串sub出現的最低索引。該方法返回整數型別的輸出陣列。如果找不到sub,則引發ValueError異常。第一個引數是輸入陣列,第二個引數是要搜尋的子字串。第三個和第四個引數是可選引數,其中start和end的解釋與切片表示法相同。
步驟
首先,匯入所需的庫:
import numpy as np
建立一個一維字串陣列:
arr = np.array(['KATIE', 'KATE', 'CRATE'])
顯示我們的陣列:
print("Array...\n",arr)獲取資料型別:
print("\nArray datatype...\n",arr.dtype)
獲取陣列的維度:
print("\nArray Dimensions...\n",arr.ndim)獲取陣列的形狀:
print("\nOur Array Shape...\n",arr.shape)
獲取陣列的元素個數:
print("\nNumber of elements in the Array...\n",arr.size)使用numpy.char.index()方法返回字串中子字串sub出現的最低索引。該方法返回整數型別的輸出陣列。如果找不到sub,則引發ValueError異常:
print("\nResult (index() method)...\n",np.char.index(arr, 'AT', start = 1, end= 4))
示例
import numpy as np
# Create a One-Dimensional array of strings
arr = np.array(['KATIE', 'KATE', 'CRATE'])
# Displaying our array
print("Array...\n",arr)
# Get the datatype
print("\nArray datatype...\n",arr.dtype)
# Get the dimensions of the Array
print("\nArray Dimensions...\n",arr.ndim)
# Get the shape of the Array
print("\nOur Array Shape...\n",arr.shape)
# Get the number of elements of the Array
print("\nNumber of elements in the Array...\n",arr.size)
# Return the lowest index in the string where substring sub is found using the numpy.char.index() method in Python Numpy
# The method returns the output array of ints. Raises ValueError if sub is not found.
print("\nResult (index() method)...\n",np.char.index(arr, 'AT', start = 1, end= 4))輸出
Array... ['KATIE' 'KATE' 'CRATE'] Array datatype... <U5 Array Dimensions... 1 Our Array Shape... (3,) Number of elements in the Array... 3 Result (index() method)... [1 1 2]
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