正則表達式

 1 import re
 2 
 3 # ============= 筆記 =================
 4 '''
 5 re.match只匹配字符串的開始，若是字符串開始不符合正則表達式，則匹配失敗，函數返回None；
 6 而re.search匹配整個字符串，直到找到一個匹配。
 7 
 8 
 9 # ==================================== #
10 '''
11 #  p:模式  s:要匹配的字符串
12 
13 
14 def match(p, s):
15     matchobj = re.search(p, s)
16     if matchobj:
17         print('匹配成功')
18         print("匹配的字符串是：", matchobj.group())
19         #print("匹配的字符串的索引是：",matchobj.start(),matchObj.end())
20     else:
21         print("匹配失敗")
22 
23 
24 def sub(in_file, out_file):
25     with open(out_file, "w", encoding="utf-8") as f_write:
26         for line in open(in_file):
27             sub_line = re.sub('NV', 'GN', line)
28             print(sub_line)
29             f_write.write(sub_line)
30         f_write.close()
31 
32 
33 pattern = 'abc'
34 string = 'hello abc dog'
35 match(pattern, string)
36 
37 in_file = './in.txt'
38 out_file = './out.txt'
39 sub(in_file, out_file)