| search( | pattern, string[, flags]) |
None if pattern is not found in the string. (Note: A match does not necessarily contain part of the given string. For example, these patterns matches any string: r'', r'y*'.)
Here's an example of using search():
result=re.search(r'\w+@\w+\.com', 'long text xyz@xyz.com long')
if result:
print "contains email!"
print result.group()
else:
print "no!"
Note: pattern string must be enclosed as raw string like r'...', otherwise, backslashes in it must be escaped. For example, to search for a sequence of tabs, use re.search(r'\t+') or re.search('\\t+').
The optional second argument (flags) modifies the meaning of the given pattern. The flags can be any of I, L, M, S, U, S. They
can be combined with the | operator. For example,
re.search(pat,re.M|re.U) creates a regex pattern that matches
multiple lines of a Unicode string. Each of the flag is detailed below.
NEED EXAMPLE HERE. Basically, need to explicitly indicate what exactly "local" means in terms of actual code or some explicit settings.
result=re.search(r'\w+', u'真善美αβγ!',re.U)
if result:
print result.group().encode('utf8')
else:
print "no match"
Note that Python re module also allows unicode in the pattern string. Just be sure to use the unicode prefix 'u' to the pattern string. For Example:
result=re.findall(ur'善+', u'真善美αβγ!',re.U)
print result[0].encode('utf8')
| match( | pattern, string[, flags]) |
Note: Match() is not exactly equivalent to Search() with "^". For example:
re.search(r'^B', 'A\nB',re.M) # succeeds re.match(r'B', 'A\nB',re.M) # fails
| split( | pattern, string[, maxsplit = 0]) |
re.split(r' +', 'what do you think') # returns ['what', 'do', 'you', 'think']
If the boundary pattern is enclosed in parenthesis, then it is included in the returned list. For Example:
re.split(r'( +)', 'what do you think') # returns ['what', ' ', 'do', ' ', 'you', ' ', 'think']
If there are more than one capturing parenthesis in pattern, they are all included in the returned list in sequence. For Example:
re.split(r'( +)(@+)', 'what @@do @@you @@think') # returns ['what', ' ', '@@', 'do', ' ', '@@', 'you', ' ', '@@', 'think']
If the optional maxsplit is given, then the returned list's length is no more than maxsplit.
| findall( | pattern, string[, flags]) |
re.findall(r'@+', 'what @@@do @@you @think') # returns ['@@@', '@@', '@']
re.findall(r'( +)(@+)', 'what @@@do @@you @think')
# returns [(' ', '@@@'), (' ', '@@'), (' ', '@')]
re.findall(r'\b', 'what @@@do @@you @think') # returns ['', '', '', '', '', '', '', '']
need another example here showing what is meant by "unless they touch the beginning of another match."
| finditer( | pattern, string[, flags]) |
for matched in re.finditer(r'(\w+)', 'what do you think'):
print matched.group()
| sub( | pattern, repl, string[, count]) |
newstr=re.sub(r'([^-]+)--(.+)$', r'\1--Me, not \2','"what do you mean?" --A Sage') # returns: "what do you mean?" --Me, not A Sage
def fun(matchObj):
if matchObj.group(0) == '--A Sage':
return '--Me'
else:
return '--Some Joe'
newstr=re.sub(r'--.+$', fun,'"what do you mean?" --xyz')
print newstr # prints: "what do you mean?" --Some Joe
The first argument pattern may be a string or an regex
object. If you need to specify regular expression flags, you must
use a regex object. Alternatively, you can embed a flag in your regex pattern by “(?iLmsux)” in the beginning of your pattern. For
example, "sub("(?i)b+", "x", "bbbb BBBB")"
returns 'x x'. (
See regex pattern syntax for detail.
)
The optional argument count is the maximum number of pattern occurrences to be replaced.
In addition to character escapes and backreferences as described above, "\g<name>" will use the substring matched by the group named "name", as defined by the (?P<name>...) syntax. "\g<number>" uses the corresponding group number; "\g<2>" is therefore equivalent to "\2", but isn't ambiguous in a replacement such as "\g<2>0". "\20" would be interpreted as a reference to group 20, not a reference to group 2 followed by the literal character "0". The backreference "\g<0>" substitutes in the entire substring matched by the pattern.
| subn( | pattern, repl, string[, count]) |
(new_string, number_of_subs_made).
| escape( | string) |
Page created: 2005-04, by Xah Lee. For copyright and terms, see terms.html