如何捕获整数与其后继之间的任何内容

Question

如何捕获整数与其后继者之间的任何内容？例如，假设我们要在b3c中捕获1和2之间的a1b3c2d。以下代码为我们提供了b3c2d。

'a1b3c2d' =~ / (\d+) (.+) (?{ $1 + 1 }) /x;

print $2, "\n";

Answer 1

您正在寻找(??{ ... })，它将代码块的结果解释为正则表达式，而不是(?{ ... })，它总是成功作为断言。并且您可能希望在两者之间使用非贪婪的量词，以便它在以下数字的第一个匹配处停止。放在一起，/ (\d+) (.+?) (??{ $1 + 1 }) /x完成工作。

您可能还希望在代码断言之前和之后添加否定断言，以防止匹配“不完整”整数 - 即您不希望将“21”的第一个数字视为“2”。那会给出

/ (\d+) (.+?) (?<!\d) (??{ $1 + 1 }) (?!\d) /x

共

Answer 2

该构造中需要两个问号。只需一个，只需将代码的值放入# installing zipimport hook import zipimport # builtin # installed zipimport hook # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site.py import site # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/os.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/os.py import os # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/os.pyc import errno # builtin import posix # builtin # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/posixpath.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/posixpath.py import posixpath # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/posixpath.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/stat.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/stat.py import stat # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/stat.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/genericpath.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/genericpath.py import genericpath # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/genericpath.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/warnings.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/warnings.py import warnings # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/warnings.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/linecache.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/linecache.py import linecache # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/linecache.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/types.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/types.py import types # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/types.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/UserDict.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/UserDict.py import UserDict # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/UserDict.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_abcoll.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_abcoll.py import _abcoll # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_abcoll.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/abc.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/abc.py import abc # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/abc.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_weakrefset.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_weakrefset.py import _weakrefset # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_weakrefset.pyc import _weakref # builtin # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/copy_reg.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/copy_reg.py import copy_reg # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/copy_reg.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/traceback.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/traceback.py import traceback # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/traceback.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sysconfig.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sysconfig.py import sysconfig # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sysconfig.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/re.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/re.py import re # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/re.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_compile.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_compile.py import sre_compile # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_compile.pyc import _sre # builtin # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_parse.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_parse.py import sre_parse # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_parse.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_constants.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_constants.py import sre_constants # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/sre_constants.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_sysconfigdata.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_sysconfigdata.py import _sysconfigdata # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_sysconfigdata.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_osx_support.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_osx_support.py import _osx_support # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_osx_support.pyc # zipimport: found 135 names in /Library/Python/2.7/site-packages/setuptools-3.5.1-py2.7.egg import encodings # directory /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/__init__.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/__init__.py import encodings # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/__init__.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/codecs.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/codecs.py import codecs # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/codecs.pyc import _codecs # builtin # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/aliases.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/aliases.py import encodings.aliases # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/aliases.pyc # /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/utf_8.pyc matches /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/utf_8.py import encodings.utf_8 # precompiled from /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/utf_8.pyc Python 2.7.6 (v2.7.6:3a1db0d2747e, Nov 10 2013, 00:42:54) [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin Type "help", "copyright", "credits" or "license" for more information. Traceback (most recent call last): File "<string>", line 1, in <module> ImportError: No module named pytz # clear __builtin__._ # clear sys.path # clear sys.argv # clear sys.ps1 # clear sys.ps2 # clear sys.exitfunc # clear sys.exc_type # clear sys.exc_value # clear sys.exc_traceback # clear sys.last_type # clear sys.last_value # clear sys.last_traceback # clear sys.path_hooks # clear sys.path_importer_cache # clear sys.meta_path # clear sys.flags # clear sys.float_info # restore sys.stdin # restore sys.stdout # restore sys.stderr # cleanup __main__ # cleanup[1] encodings # cleanup[1] site # cleanup[1] sysconfig # cleanup[1] abc # cleanup[1] _weakrefset # cleanup[1] sre_constants # cleanup[1] _codecs # cleanup[1] _warnings # cleanup[1] zipimport # cleanup[1] _sysconfigdata # cleanup[1] encodings.utf_8 # cleanup[1] _osx_support # cleanup[1] codecs # cleanup[1] signal # cleanup[1] traceback # cleanup[1] posix # cleanup[1] encodings.aliases # cleanup[1] exceptions # cleanup[1] _weakref # cleanup[1] re # cleanup[1] sre_compile # cleanup[1] _sre # cleanup[1] sre_parse # cleanup[2] copy_reg # cleanup[2] posixpath # cleanup[2] errno # cleanup[2] _abcoll # cleanup[2] types # cleanup[2] genericpath # cleanup[2] stat # cleanup[2] warnings # cleanup[2] UserDict # cleanup[2] os.path # cleanup[2] linecache # cleanup[2] os # cleanup sys # cleanup __builtin__ # cleanup ints: 827 unfreed ints # cleanup floats 并返回匹配

$^R

输出

'a1b3c2d' =~ / (\d+) (.+) (??{ $1 + 1 }) /x;

print $2, "\n";