可以說我有一個正則表達式：回溯正則表達式
match = re.search(pattern, content)
if not match:
raise Exception, 'regex traceback' # i want to throw here the regex matching process.
如果正則表達式fails to match然後我想在exception扔它的工作，並在那裏沒有正則表達式模式匹配，在哪個階段等。是否有可能實現所需的功能？
我有事情，可以幫助我我的代碼中調試複雜的正則表達式模式。
這對你有幫助嗎？ ：
import re
li = ('ksjdhfqsd\n'
'5 12478 abdefgcd ocean__12 ty--\t\t ghtr789\n'
'qfgqrgqrg',
'6 48788 bcfgdebc atlantic__7899 %fg#\t\t ghtu12340\n',
'2 47890 bbcedefg arctic__124 **juyf\t\t ghtr89877',
'9 54879 bbdecddf antarctic__13 18:13pomodoro\t\t ghtr6798',
'ksjdhfqsd\n'
'5 12478 abdefgcd ocean__1247101247887 ty--\t\t ghtr789\n'
'qfgqrgqrg',
'6 48788 bcfgdebc atlantic__7899 %fg#\t\t ghtu12940\n',
'25 47890 bbcedefg arctic__124 **juyf\t\t ghtr89877',
'9 54879 bbdeYddf antarctic__13 18:13pomodoro\t\t ghtr6798')
tupleRE = ('^\d',
' ',
'\d{5}',
' ',
'[abcdefghi]+',
' ',
'(?=[a-z\d_ ]{14} [^ ]+\t\t ght)',
'[a-z]+',
'__',
'[\d]+',
' +',
'[^\t]+',
'\t\t',
' ',
'ght',
'(r[5-9]+|u[0-4]+)',
'$')
def REtest(ch, tuplRE, flags = re.MULTILINE):
for n in xrange(len(tupleRE)):
regx = re.compile(''.join(tupleRE[:n+1]), flags)
testmatch = regx.search(ch)
if not testmatch:
print '\n -*- tupleRE :\n'
print '\n'.join(str(i).zfill(2)+' '+repr(u)
for i,u in enumerate(tupleRE[:n]))
print ' --------------------------------'
# tupleRE doesn't works because of element n
print str(n).zfill(2)+' '+repr(tupleRE[n])\
+" doesn't match anymore from this ligne "\
+str(n)+' of tupleRE'
print '\n'.join(str(n+1+j).zfill(2)+' '+repr(u)
for j,u in enumerate(tupleRE[n+1:
min(n+2,len(tupleRE))]))
for i in xrange(n):
match = re.search(''.join(tupleRE[:n-i]),ch, flags)
if match:
break
matching_portion = match.group()
matching_li = '\n'.join(map(repr,
matching_portion.splitlines(True)[-5:]))
fin_matching_portion = match.end()
print ('\n\n -*- Part of the tested string which is concerned :\n\n'
'######### matching_portion ########\n'+matching_li + '\n'
'##### end of matching_portion #####\n'
'-----------------------------------\n'
'######## unmatching_portion #######')
print '\n'.join(map(repr,
ch[fin_matching_portion:
fin_matching_portion+300].splitlines(True)))
break
else:
print '\n SUCCES . The regex integrally matches.'
for x in li:
print ' -*- Analyzed string :\n%r' % x
REtest(x,tupleRE)
print '\nmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm'
結果
-*- Analyzed string :
'ksjdhfqsd\n5 12478 abdefgcd ocean__12 ty--\t\t ghtr789\nqfgqrgqrg'
SUCCESS . The regex integrally matches.
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
-*- Analyzed string :
'6 48788 bcfgdebc atlantic__7899 %fg#\t\t ghtu12340\n'
SUCCESS . The regex integrally matches.
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
-*- Analyzed string :
'2 47890 bbcedefg arctic__124 **juyf\t\t ghtr89877'
SUCCESS . The regex integrally matches.
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
-*- Analyzed string :
'9 54879 bbdecddf antarctic__13 18:13pomodoro\t\t ghtr6798'
SUCCESS . The regex integrally matches.
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
-*- Analyzed string :
'ksjdhfqsd\n5 12478 abdefgcd ocean__1247101247887 ty--\t\t ghtr789\nqfgqrgqrg'
-*- tupleRE :
00 '^\\d'
01 ' '
02 '\\d{5}'
03 ' '
04 '[abcdefghi]+'
05 ' '
--------------------------------
06 '(?=[a-z\\d_ ]{14} [^ ]+\t\t ght)' doesn't match anymore from this ligne 6 of tupleRE
07 '[a-z]+'
-*- Part of the tested string which is concerned :
######### matching_portion ########
'5 12478 abdefgcd '
##### end of matching_portion #####
-----------------------------------
######## unmatching_portion #######
'ocean__1247101247887 ty--\t\t ghtr789\n'
'qfgqrgqrg'
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
-*- Analyzed string :
'6 48788 bcfgdebc atlantic__7899 %fg#\t\t ghtu12940\n'
-*- tupleRE :
00 '^\\d'
01 ' '
02 '\\d{5}'
03 ' '
04 '[abcdefghi]+'
05 ' '
06 '(?=[a-z\\d_ ]{14} [^ ]+\t\t ght)'
07 '[a-z]+'
08 '__'
09 '[\\d]+'
10 ' +'
11 '[^\t]+'
12 '\t\t'
13 ' '
14 'ght'
15 '(r[5-9]+|u[0-4]+)'
--------------------------------
16 '$' doesn't match anymore from this ligne 16 of tupleRE
-*- Part of the tested string which is concerned :
######### matching_portion ########
'6 48788 bcfgdebc atlantic__7899 %fg#\t\t ghtu12'
##### end of matching_portion #####
-----------------------------------
######## unmatching_portion #######
'940\n'
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
-*- Analyzed string :
'25 47890 bbcedefg arctic__124 **juyf\t\t ghtr89877'
-*- tupleRE :
00 '^\\d'
--------------------------------
01 ' ' doesn't match anymore from this ligne 1 of tupleRE
02 '\\d{5}'
-*- Part of the tested string which is concerned :
######### matching_portion ########
'2'
##### end of matching_portion #####
-----------------------------------
######## unmatching_portion #######
'5 47890 bbcedefg arctic__124 **juyf\t\t ghtr89877'
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
-*- Analyzed string :
'9 54879 bbdeYddf antarctic__13 18:13pomodoro\t\t ghtr6798'
-*- tupleRE :
00 '^\\d'
01 ' '
02 '\\d{5}'
03 ' '
04 '[abcdefghi]+'
--------------------------------
05 ' ' doesn't match anymore from this ligne 5 of tupleRE
06 '(?=[a-z\\d_ ]{14} [^ ]+\t\t ght)'
-*- Part of the tested string which is concerned :
######### matching_portion ########
'9 54879 bbde'
##### end of matching_portion #####
-----------------------------------
######## unmatching_portion #######
'Yddf antarctic__13 18:13pomodoro\t\t ghtr6798'
mwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwmwm
是我已經使用它，並找到有幫助，但它有點複雜，但：p –
我以前使用Kodos（http://kodos.sourceforge.net/about.html）來執行RegEx調試。這不是理想的解決方案，因爲您需要運行時的一些東西，但它可能對您有所幫助。
如果您需要測試re，您可以使用羣組，然後* ... as（sometext）* 與您所需的正則表達式一起使用，然後您應該能夠拔出失敗位置
，然後利用以下，作爲
POS 被傳遞到搜索（）或RegexObject的匹配（）方法中的POS的值上python.org說明。這是RE引擎開始尋找匹配的字符串的索引。
endpos 傳遞給> RegexObject的search（）或match（）方法的endpos的值。這是RE引擎不會去的字符串的索引。
lastindex 最後一個匹配的捕獲組的整數索引，或者如果沒有組完全匹配，則返回None。例如，如果將表達式（a）b，（（a）（b））和（（ab））應用於字符串「ab」，則lastindex == 1，而表達式（a）（b）將如果應用於相同的字符串，則lastindex == 2。
lastgroup 上次匹配的捕獲組的名稱，或者如果該組沒有名稱，或者根本沒有組匹配，則爲None。
re match（）或search（）方法生成此MatchObject實例的正則表達式對象。
字符串 傳遞給match（）或search（）的字符串。
所以一個很簡單的例子
>>> m1 = re.compile(r'the real thing')
>>> m2 = re.compile(r'(the)* (real)* (thing)*')
>>> if not m1.search(mytextvar):
>>> res = m2.search(mytextvar)
>>> print res.lastgroup
>>> #raise my exception
它看起來你有什麼工作。你測試過了嗎？ –
看看[獲取python正則表達式解析樹來調試您的正則表達式]（http://stackoverflow.com/questions/101268/hidden-features-of-python/143636#143636） – agf