蟒蛇正則表達式應用re.sub錯誤

Question

我有可能有括號混合的.csv文件：

line = "fdf,dfdf,(1,2,3,4,5),(ss,dd)," 

現在我要全部更換爲（）用「」，這樣它看起來像這樣：

line = 'fdf,dfdf,"1,2,3,4,5","ss,dd",' 

我的代碼是：

line=re.sub(',(', ',"', line) 
line=re.sub('),', '",', line) 

但是我得到這個錯誤：

... 
File "/usr/local/Python-2.7/lib/python2.7/re.py", line 151, in sub 
    return _compile(pattern, flags).sub(repl, string, count) 
    File "/usr/local/Python-2.7/lib/python2.7/re.py", line 242, in _compile 
    raise error, v # invalid expression 
sre_constants.error: unbalanced parenthesis 

這裏有什麼問題？

Answer 1

(在正則表達式中有特殊含義，您可以使用\(將它們轉義或使用方括號[]括號。

>>> import re 
>>> strs = "fdf,dfdf,(1,2,3,4,5),(ss,dd)," 
>>> re.sub(r"[()]",'"',strs) 
'fdf,dfdf,"1,2,3,4,5","ss,dd",' 
#or 
>>> re.sub(r"\(|\)",'"',strs) 
'fdf,dfdf,"1,2,3,4,5","ss,dd",' 

Answer 2

如何回合只是簡單的字符串替換

print strs.replace("(",'"').replace(")",'"') 

不需要正則表達式這個

Some people, when confronted with a problem, think 「I know, I'll use regular expressions.」 Now they have two problems.

Answer 3

另一個是考慮這個..

import re 
re.sub('\)', '\"', re.sub('\(', '\"', line)) 

什麼你做的是一次取代一個幽靈然後替換另一個。