目录

• 字符串的索引，获取
• 字符串的find与index函数

字符串的索引与获取

• 索引规则与列表相同
• 切片和索引的获取与列表相同
• 无法通过索引修改与删除
• 字符串不可修改
  

name = 'dewei'
name[0] -> d 
name[:2] -> de

字符串的find与index函数

• 功能: 获取元素的索引位置
• 用法∶
  • string.index(item)
  • string.find(item)
  • item: 查询个数的元素,返回索引位置

In [85]: info = 'my name is insane'

In [86]: info.index('insane')
Out[86]: 11

In [87]: info.find ('insane')
Out[87]: 11

find与index的区别

• find如果获取不到，返回-1
• index如果获取不到，直接报错

In [88]: info = 'my name is insane'
In [89]: info.find ( 'xiaoming' )
Out [89]: -1
In [90]: info.index( 'xiaoming')
---------------
ValueError
Traceback (most recent call last)
<ipython-input-90-ac642654eb73> in module>
----> 1 info.index( 'xiaoming' )
ValueError: substring not found

实战

# coding:utf-8

name = 'insane'

temp = []
temp.append(name[0])
temp.append(name[1])
temp.append(name[2])
temp.append(name[3])
temp.append(name[4])
temp.append(name[5])
print(temp)
temp.reverse()
print(temp)

new_name = '%s%s%s%s%s'%(temp[0],temp[1],temp[2],temp[3],temp[4])

temp_01 = temp.extend(name)
print(temp_01)
temp.reverse()
print(temp_01)
new_name_01 = name[::-1]
print(new_name_01)

result = new_name.find('in')
print(result)
result = new_name.find('en')
print(result)

result_index = new_name.index('ni')
print(result)  # 会报错

Traceback (most recent call last):
  File "D:/My_Files/Python Project/pythonlean/python_list/str_index.py", line 30, in <module>
    result_index = new_name.index('ni')
ValueError: substring not found
['i', 'n', 's', 'a', 'n', 'e']
['e', 'n', 'a', 's', 'n', 'i']
None
None
enasni
-1
0

Process finished with exit code 1