從字符串中提取方括號內的文本

Question

有人可以幫我從字符串中去掉字符，只留下「[....]」中的字符嗎？

For example: 

a = newyork_74[mylocation] 

b = # strip the frist characters until you reach the first bracket [ 

c = [mylocation] 

Answer 1

假設沒有嵌套結構，一種方法是使用itertools.dropwhile，

>>> from itertools import dropwhile 
>>> b = ''.join(dropwhile(lambda c: c != '[', a)) 
>>> b 
'[mylocation]' 

另一個是使用regexs，

>>> import re 
>>> pat = re.compile(r'\[.*\]') 
>>> b = pat.search(a).group(0) 
>>> b 
'[mylocation]' 

Answer 2

像這樣：

>>> import re 
>>> strs = "newyork_74[mylocation]" 
>>> re.sub(r'(.*)?(\[)','\g<2>',strs) 
'[mylocation]'