To remember python regex easily, we organise python regex notes from concrete to abstract, and from simple to sophisticated.
I, Important character:
1, Quantitive character:
? :[0,1], *:[0,infi), +:(0,infi), {n}:[n rep], {m,}:[m, infi), {,n}:[0,n], {m,n}:[m,n],
? (nogreedy option)
2, Begin and End:
^: beginning, $: ending
3, Making own character class:
[abc] ,[^abc]: ^ rep non
4, Character classes:
\d,\D,\s,\S,\w,\W
5: dot (or wildcard) character:
. , .*, (.*) ? : rep nongreedy fashion
II, Usefull regex arguments
1, re.DOTALL : match all characters, including the newline character.
2, re.I (re.IGNORECASE): ignore uppercase
3, re.VERBOSE : spread the regex over multiple lines with comments.
4, | : we could use pipe character to cobine all three above arguments.
III, generate regex procedure:
1, regex = re.compile(r"")
2.1.1, regex.search("")
2.1.2, regex.search("").group(), (or regex.search("").group(No.)), greedy defalut
2.2, regex.findall("")
2.3 regex.sub("")
3 , re.compile(r‘‘‘(
)‘‘‘, re.VERBOSE) : to manage more complex regrexes.
6: re.DOTALL, re.I
原文：http://www.cnblogs.com/xuezoushi/p/5471070.html