1 >>> name = "my name is LiSi"
 2  # 首字母大寫 capitalize()
 3 >>> name.capitalize()    
 4 'My name is lisi'
 5 
 6  # 字串全部大寫 upper()
 7 >>> name.upper()        
 8 'MY NAME IS LISI'
 9 
10  # 字串全部小寫 lower()
11 >>> name.lower()        
12 'my name is lisi'
13 
14  # 在程式需要判斷不區分大小寫的時候,肯定能用上(如常見驗證碼)
 

15  # 如下例子,寫一個無限迴圈,輸入內容是Q則退出,不分大小寫,這個例子使用了上面字串轉換為大寫的方法 upper()
16 >>>while 1:
17 ...     content = input("input is 'q',exit... :")
18 ...     if content.upper() == 'Q':
19 ...             break
20 ...     print('you's is input %s' % (content))
21 ... 
22 input is 'q',exit... :123456
23 you'
 
s is input 123456...
24 input is 'q',exit... :abc
25 you's is input...
26 input is 'q',exit... :q
27 >>>
28 
29  # 每個空格隔開的首字母大寫   title()
30 >>> s = "i like my family!"
31 >>> s.title()
32 'I Like My Family!'
33 
34 >>> s = "I Like My Family!"
35  # 指定字元長度,如果超出,對稱的在左右兩邊加上指定字元 center()
 

36 >>> s.center(41, "*")
37  # 輸出結果總共加起來剛好41個字元(左右兩邊)
38 '************I Like My Family!************'     
39  # 輸出結果總共加起來剛好41個字元(只加在右邊) ljust()
40 >>> s.ljust(41, "*")
41 'I Like My Family!************************'
42  # 輸出結果總共加起來剛好41個字元(只加在左邊) rjust()
43 >>> s.rjust(41, "*")
44 '************************I Like My Family!' 
45 
46 >>> s = "I like my Family"
47  # 替換字元 replace()
48 >>> s.replace("Family", "Mother")
49 'I like my Mother'
50  
51  >>> s = "I like my Family"
52  # 切片split()  刀是my ,切完後的字串是列表 ,列表裝的是字串
53 >>> s.split("my")
54 ['I like ', ' Family']
55  # 這次刀是空格,將"I like my Family" 以空格為刀,切成4塊
56 >>> s.split(" ")
57 ['I', 'like', 'my', 'Family']
58 
59  # 判斷字串長度 len()
60 >>> s = "my name is lisi"
61 >>> len(s)
62 15
63 >>> s = "123456789"
64 >>> len(s)
65 9
66 --------------------- 
67 作者：qq-6909283 
68 來源：CSDN 
69 原文：https://blog.csdn.net/qq_33352948/article/details/84066155 
70 版權宣告：本文為博主原創文章，轉載請附上博文連結！

常用的字串操作就這些,其他的不常見的就不一一列舉了,後面有需要的再完善