例 1 ：使用正則表達式提取字符串中的電話號碼。

 1 import re
 2 
 3 telNumber = ‘‘‘Suppose my Phone No. is 0535-1234567,yours is 010-12345678,his is 025-87654321.‘‘‘
 4 pattern = re.compile(r‘(\d{3,4})-(\d{7,8})‘)
 5 
 6 index = 0
 7 while True:
 8     matchResult = pattern.search(telNumber,index)  #從指定位置開始匹配
 9     if not matchResult:
 
10         break
11     print(‘-‘ * 30)
12     print(‘Success:‘)
13     for i in range(3):
14         print(‘Sarched content:‘,matchResult.group(i),‘Start from:‘,matchResult.start(i),‘End at:‘,
                  matchResult.end(i),‘Its span is:‘,matchResult.span(i))
15     index = matchResult.end(2)  #
 
指定下次匹配的開始位置
16     
17 ‘‘‘
18 ------------------------------
19 Success:
20 Sarched content: 0535-1234567 Start from: 24 End at: 36 Its span is: (24, 36)
21 Sarched content: 0535 Start from: 24 End at: 28 Its span is: (24, 28)
22 Sarched content: 1234567 Start from: 29 End at: 36 Its span is: (29, 36)
 
23 ------------------------------
24 Success:
25 Sarched content: 010-12345678 Start from: 46 End at: 58 Its span is: (46, 58)
26 Sarched content: 010 Start from: 46 End at: 49 Its span is: (46, 49)
27 Sarched content: 12345678 Start from: 50 End at: 58 Its span is: (50, 58)
28 ------------------------------
29 Success:
30 Sarched content: 025-87654321 Start from: 66 End at: 78 Its span is: (66, 78)
31 Sarched content: 025 Start from: 66 End at: 69 Its span is: (66, 69)
32 Sarched content: 87654321 Start from: 70 End at: 78 Its span is: (70, 78)
33 ‘‘‘

　　例 2：使用正則表達式提取Python程序中的類名、函數名已經變量名等標識符。

　　將下面的代碼保存為FindIdentifiersFromPyFile.py，在名利提示符環境中使用命令“Python FindIdentifiersFromPyFile.py 目標文件名”查找並輸出目標文件中的標識符。

5.2.3 案例精選