## Python正则表达式集锦

if 你只有5min:

return

else:

Python正则表达式指南

Python正则表达式的用法

Python正则表达式操作指南

match和search的区别

Python提供了两种不同的原始操作：match和search。match是从字符串的起点开始做匹配，而search（perl默认）是从字符串做任意匹配。

注意：当正则表达式是' ^ '开头时，match与search是相同的。match只有当且仅当被匹配的字符串开头就能匹配 或 从pos参数的位置开始就能匹配 时才会成功。如下：

>>> import re

>>> m = re.search("(book)+","mebookbookme")

>>> m.group()

'bookbook'

>>> m.groups()

('book',)

>>> re.findall("(book)+","mebookbookme")

['book']


>>> m = re.search("((?:book)+)","mebookbookme")

>>> m.group()

'bookbook'

>>> m.groups()

('bookbook',)

>>> re.findall("((?:book)+)","mebookbookme")

['bookbook']


>>> m = re.search("(book+)","mebookbookme")

>>> m.group()

'book'

>>> m.groups()

('book',)

>>> re.findall("(book+)","mebookbookme")

['book', 'book']

python非贪婪、多行匹配正则表达式例子

Python 正则提取并赋值的问题

Python对unicode文件的读写和使用正则表达式

python类库31[正则表达式]

^[1-9]\d*$//匹配正整数 ^-[1-9]\d*$ 　 //匹配负整数
^-?[1-9]\d*$//匹配整数 ^[1-9]\d*|0$　 //匹配非负整数（正整数 + 0）
^-[1-9]\d*|0$//匹配非正整数（负整数 + 0） ^[1-9]\d*\.\d*|0\.\d*[1-9]\d*$　　 //匹配正浮点数
^-([1-9]\d*\.\d*|0\.\d*[1-9]\d*)$//匹配负浮点数 ^-?([1-9]\d*\.\d*|0\.\d*[1-9]\d*|0?\.0+|0)$　 //匹配浮点数
^[1-9]\d*\.\d*|0\.\d*[1-9]\d*|0?\.0+|0$//匹配非负浮点数（正浮点数 + 0） ^(-([1-9]\d*\.\d*|0\.\d*[1-9]\d*))|0?\.0+|0$　　//匹配非正浮点数（负浮点数 + 0）

^[A-Za-z]+$//匹配由26个英文字母组成的字符串 ^[A-Z]+$　　//匹配由26个英文字母的大写组成的字符串
^[a-z]+$//匹配由26个英文字母的小写组成的字符串 ^[A-Za-z0-9]+$　　//匹配由数字和26个英文字母组成的字符串
^\w+$//匹配由数字、26个英文字母或者下划线组成的字符串 匹配中文字符的正则表达式： [\u4e00-\u9fa5] 评注：匹配中文还真是个头疼的事，有了这个表达式就好办了 匹配双字节字符(包括汉字在内)：[^\x00-\xff] 评注：可以用来计算字符串的长度（一个双字节字符长度计2，ASCII字符计1） 匹配空白行的正则表达式：\n\s*\r 评注：可以用来删除空白行 匹配HTML标记的正则表达式：<(\S*?)[^>]*>.*?</\1>|<.*? /> 评注：网上流传的版本太糟糕，上面这个也仅仅能匹配部分，对于复杂的嵌套标记依旧无能为力 匹配首尾空白字符的正则表达式：^\s*|\s*$

the end of the string.
"*"      Matches 0 or more (greedy) repetitions of the preceding RE.
Greedy means that it will match as many repetitions as possible.
"+"      Matches 1 or more (greedy) repetitions of the preceding RE.
"?"      Matches 0 or 1 (greedy) of the preceding RE.
*?,+?,?? Non-greedy versions of the previous three special characters.
{m,n}    Matches from m to n repetitions of the preceding RE.
{m,n}?   Non-greedy version of the above.
"\\"     Either escapes special characters or signals a special sequence.
[]       Indicates a set of characters.
A "^" as the first character indicates a complementing set.
"|"      A|B, creates an RE that will match either A or B.
(...)    Matches the RE inside the parentheses.
The contents can be retrieved or matched later in the string.
(?iLmsux) Set the I, L, M, S, U, or X flag for the RE (see below).
(?:...)  Non-grouping version of regular parentheses.
(?P<name>...) The substring matched by the group is accessible by name.
(?P=name)     Matches the text matched earlier by the group named name.
(?#...)  A comment; ignored.
(?=...)  Matches if ... matches next, but doesn't consume the string.
(?!...)  Matches if ... doesn't match next.
(?<=...) Matches if preceded by ... (must be fixed length).
(?<!...) Matches if not preceded by ... (must be fixed length).
(?(id/name)yes|no) Matches yes pattern if the group with id/name matched,
the (optional) no pattern otherwise.

The special sequences consist of "\\" and a character from the list
below.  If the ordinary character is not on the list, then the
resulting RE will match the second character.
\number  Matches the contents of the group of the same number.
\A       Matches only at the start of the string.
\Z       Matches only at the end of the string.
\b       Matches the empty string, but only at the start or end of a word.
\B       Matches the empty string, but not at the start or end of a word.
\d       Matches any decimal digit; equivalent to the set [0-9].
\D       Matches any non-digit character; equivalent to the set [^0-9].
\s       Matches any whitespace character; equivalent to [ \t\n\r\f\v].
\S       Matches any non-whitespace character; equiv. to [^ \t\n\r\f\v].
\w       Matches any alphanumeric character; equivalent to [a-zA-Z0-9_].
With LOCALE, it will match the set [0-9_] plus characters defined
as letters for the current locale.
\W       Matches the complement of \w.
\\       Matches a literal backslash.

This module exports the following functions:
match    Match a regular expression pattern to the beginning of a string.
search   Search a string for the presence of a pattern.
sub      Substitute occurrences of a pattern found in a string.
subn     Same as sub, but also return the number of substitutions made.
split    Split a string by the occurrences of a pattern.
findall  Find all occurrences of a pattern in a string.
finditer Return an iterator yielding a match object for each match.
compile  Compile a pattern into a RegexObject.
purge    Clear the regular expression cache.
escape   Backslash all non-alphanumerics in a string.

Some of the functions in this module takes flags as optional parameters:
I  IGNORECASE  Perform case-insensitive matching.
L  LOCALE      Make \w, \W, \b, \B, dependent on the current locale.
M  MULTILINE   "^" matches the beginning of lines (after a newline)
as well as the string.
"\$" matches the end of lines (before a newline) as well
as the end of the string.
S  DOTALL      "." matches any character at all, including the newline.
X  VERBOSE     Ignore whitespace and comments for nicer looking RE's.
U  UNICODE     Make \w, \W, \b, \B, dependent on the Unicode locale.

This module also defines an exception 'error'.

posted on 2012-05-16 22:35  小唯THU  阅读(11106)  评论(0编辑  收藏

• 随笔 - 122
• 文章 - 6
• 评论 - 90
• 引用 - 0