Python regular expression match count FindAll usage

The number of matches is defined with {}

Re.search can generate group () that can access the string for each group

The result of Re.findall is a list of elements that can be a string or a tuple

microsoft windows [version  6.1.7601] copyright   (c)  2009 microsoft corporation. All rights reserved. c:\users\user>pythonpython 3.5.2 | anaconda 4.2.0  (64-bit) |  (default, jul  5 2016, 11:41:13)  [MSC  v.1900 64 bit  (AMD64)] on win32type  "Help",  "copyright",  " Credits " or " license " for more information.>>> import re>> > str= "ATGTACGTACGTACTTTCCGT" >>> pat_str=re.compile ("(GTAC) {1}") >>> na  = re.search (pat_str,x) >>> na<_sre. Sre_match object; span= (2, 6),  match= ' GTAC ' >>>> na.group (1) ' GTAC ' >> > na.group (2) traceback  (most recent call last):  file  "<stdin > ", line 1, in <module>indexerror: no such group>>>  Na.group (0) ' GTAC ' >>>&Nbsp;for i in na.group ():...     print  (i) ... gtac>>> str_x= "Atgtacgtacgtactttccgtttccct" >>> str_y=re.compile ("(GTAC) {1}[GTAC]{5 } ") >>> na = re.search (str_y, str_x) >>> na.group () ' GTACGTACG ' > >> x= "Atgtacgtacgtactttccgtttccctgtaccccggttaat" >>> y=re.compile ("(GTAC) {1}[GTAC]{5}" ) >>> na = re.search (y,x) >>> na.group () ' GTACGTACG ' >>>  Na.group (1) ' GTAC ' >>> nas = re.findall (y, x) >>> nas[' GTAC ',  ' GTAC ']>>> re.sub (y, "nnnnnnnnn",  x) ' Atnnnnnnnnntactttccgtttccctnnnnnnnnnttaat ' >>>  x ' Atgtacgtacgtactttccgtttccctgtaccccggttaat ' >>> y=re.compile ("(GTAC) {1}[GTAC]{5}",  Flags=re. I) >>> nag=re.search (y,x) >>> nag.group () ' GTACGTACG ' >>> for i  in na.group (): ...      print  (i) ... Gtacgtacg>>> for i in na.group (1):...     print  (i) ... gtac#  use  flags=re when setting flags  and  search when using compile. The i  effect is the same as >>> na_re_i = re.search (r "(GTAC) {1}[gtac]{5}",  x, flags=re. I) >>> na_re_i<_sre. Sre_match object; span= (2, 11),  match= ' GTACGTACG ' >>>> na_re_i.group () ' GTACGTACG ' >>> na_re_i.group (1) ' GTAC ' >>> y.findall (x) [' GTAC ',  ' GTAC ']>> > y_all=re.compile ("((GTAC) {1}[gtac]{5})",  flags=re. I) >>> nas_all = re.findall (y_all, x) >>> nas_all[(' GTACGTACG ',  ' GTAC '),  (' GTACCCCGG ',  ' GTAC ')]>>>

FindAll Effect Reference:

http://blog.csdn.net/cashey1991/article/details/8875213

http://blog.163.com/[email protected]/blog/static/35265851201672431418177/

This article is from the "R and Python apps" blog, so be sure to keep this source http://matrix6ro.blog.51cto.com/1746429/1875383

Python regular expression match count FindAll usage