几天前,我处理了一个问题,即从数字字符串中删除尾随零的问题。
在这个问题的基础上,我发现这个问题很有趣,因为它将问题扩展到包含逗号的数字。
我采用了我之前编写的正则表达式模式,并对其进行了改进,以便它可以处理逗号分隔的数字作为此问题的答案。
我被我的热情和对正则表达式的喜爱所带动。我不知道结果是否完全符合Michael Prescott所表达的需求。我很想知道我的正则表达式中哪些是多余的或缺少的,并进行更正,使其更适合您。
现在,在长时间的处理该正则表达式的会话后,我的大脑感到沉重,所以我没有足够的精力来进行详细的解释。如果有任何不清楚的地方,如果有人可能足够感兴趣,请问我。
该正则表达式的构建是为了检测科学计数法表示的数字2E10甚至5,22,454.12E-00.0478,同时还删除这些数字两部分中的不必要的零。如果指数等于零,则修改数字,以便不再有指数。
我在模式中添加了一些验证,以便某些特定情况不匹配,例如
'12..57'不匹配。但在
',111'中,字符串
'111'匹配,因为前面的逗号被认为是不属于数字而是句子的逗号。
我认为逗号的管理应该得到改善,因为在印度计数中,逗号之间似乎只有两个数字。我认为这不难修正。
下面是演示我的正则表达式如何工作的代码。有两个函数,根据是否要将数字
'.1245'转换为
'0.1245'。我不会为某些数字字符串的特定情况保留错误或不需要的匹配或不匹配;然后我想知道这些情况以理解和纠正缺陷。
对于这个用Python编写的代码,我表示歉意,但正则表达式是跨语言的,我认为每个人都能理解reex的模式。
import re
regx = re.compile('(?<![\d.])(?!\.\.)(?<![\d.][eE][+-])(?<![\d.][eE])(?<!\d[.,])'
''
'([+-]?)'
'(?![\d,]*?\.[\d,]*?\.[\d,]*?)'
'(?:0|,(?=0)|(?<!\d),)*'
'(?:'
'((?:\d(?!\.[1-9])|,(?=\d))+)[.,]?'
'|\.(0)'
'|((?<!\.)\.\d+?)'
'|([\d,]+\.\d+?))'
'0*'
''
'(?:'
'([eE][+-]?)(?:0|,(?=0))*'
'(?:'
'(?!0+(?=\D|\Z))((?:\d(?!\.[1-9])|,(?=\d))+)[.,]?'
'|((?<!\.)\.(?!0+(?=\D|\Z))\d+?)'
'|([\d,]+\.(?!0+(?=\D|\Z))\d+?))'
'0*'
')?'
''
'(?![.,]?\d)')
def dzs_numbs(x,regx = regx):
if not regx.findall(x):
yield ('No match,', 'No catched string,', 'No groups.')
for mat in regx.finditer(x):
yield (mat.group(), ''.join(mat.groups('')), mat.groups(''))
def dzs_numbs2(x,regx = regx):
if not regx.findall(x):
yield ('No match,', 'No catched string,', 'No groups.')
for mat in regx.finditer(x):
yield (mat.group(),
''.join(('0' if n.startswith('.') else '')+n for n in mat.groups('')),
mat.groups(''))
NS = [' 23456000and23456000. or23456000.000 00023456000 s000023456000. 000023456000.000 ',
'arf 10000 sea10000.+10000.000 00010000-00010000. kant00010000.000 ',
' 24: 24, 24. 24.000 24.000, 00024r 00024. blue 00024.000 ',
' 8zoom8. 8.000 0008 0008. and0008.000 ',
' 0 00000M0. = 000. 0.0 0.000 000.0 000.000 .000000 .0 ',
' .0000023456 .0000023456000 '
' .0005872 .0005872000 .00503 .00503000 ',
' .068 .0680000 .8 .8000 .123456123456 .123456123456000 ',
' .657 .657000 .45 .4500000 .7 .70000 0.0000023230000 000.0000023230000 ',
' 0.0081000 0000.0081000 0.059000 0000.059000 ',
' 0.78987400000 snow 00000.78987400000 0.4400000 00000.4400000 ',
' -0.5000 -0000.5000 0.90 000.90 0.7 000.7 ',
' 2.6 00002.6 00002.60000 4.71 0004.71 0004.7100 ',
' 23.49 00023.49 00023.490000 103.45 0000103.45 0000103.45000 ',
' 10003.45067 000010003.45067 000010003.4506700 ',
' +15000.0012 +000015000.0012 +000015000.0012000 ',
' 78000.89 000078000.89 000078000.89000 ',
' .0457e10 .0457000e10 00000.0457000e10 ',
' 258e8 2580000e4 0000000002580000e4 ',
' 0.782e10 0000.782e10 0000.7820000e10 ',
' 1.23E2 0001.23E2 0001.2300000E2 ',
' 432e-102 0000432e-102 004320000e-106 ',
' 1.46e10and0001.46e10 0001.4600000e10 ',
' 1.077e-300 0001.077e-300 0001.077000e-300 ',
' 1.069e10 0001.069e10 0001.069000e10 ',
' 105040.03e10 000105040.03e10 105040.0300e10 ',
' +286E000024.487900 -78.4500e.14500 .0140E789. ',
' 081,12.40E07,95.0120 0045,78,123.03500e-0.00 ',
' 0096,78,473.0380e-0. 0008,78,373.066000E0. 0004512300.E0000 ',
' ..18000 25..00 36...77 2..8 ',
' 3.8..9 .12500. 12.51.400 ',
' 00099,111.8713000 -0012,45,83,987.26+0.000,099,88,44.or00,00,00.00must',
' 00099,44,and 0000,099,88,44.bom',
'00,000,00.587000 77,98,23,45., this,that ',
' ,111 145.20 +9,9,9 0012800 .,,. 1 100,000 ',
'1,1,1.111 000,001.111 -999. 0. 111.110000 1.1.1.111 9.909,888']
for ch in NS:
print 'string: '+repr(ch)
for strmatch, modified, the_groups in dzs_numbs2(ch):
print strmatch.rjust(20),'',modified,'',the_groups
print
结果
string: ' 23456000and23456000. or23456000.000 00023456000 s000023456000. 000023456000.000 '
23456000 23456000 ('', '23456000', '', '', '', '', '', '', '')
23456000. 23456000 ('', '23456000', '', '', '', '', '', '', '')
23456000.000 23456000 ('', '23456000', '', '', '', '', '', '', '')
00023456000 23456000 ('', '23456000', '', '', '', '', '', '', '')
000023456000. 23456000 ('', '23456000', '', '', '', '', '', '', '')
000023456000.000 23456000 ('', '23456000', '', '', '', '', '', '', '')
string: 'arf 10000 sea10000.+10000.000 00010000-00010000. kant00010000.000 '
10000 10000 ('', '10000', '', '', '', '', '', '', '')
10000. 10000 ('', '10000', '', '', '', '', '', '', '')
10000.000 10000 ('', '10000', '', '', '', '', '', '', '')
00010000 10000 ('', '10000', '', '', '', '', '', '', '')
00010000. 10000 ('', '10000', '', '', '', '', '', '', '')
00010000.000 10000 ('', '10000', '', '', '', '', '', '', '')
string: ' 24: 24, 24. 24.000 24.000, 00024r 00024. blue 00024.000 '
24 24 ('', '24', '', '', '', '', '', '', '')
24, 24 ('', '24', '', '', '', '', '', '', '')
24. 24 ('', '24', '', '', '', '', '', '', '')
24.000 24 ('', '24', '', '', '', '', '', '', '')
24.000 24 ('', '24', '', '', '', '', '', '', '')
00024 24 ('', '24', '', '', '', '', '', '', '')
00024. 24 ('', '24', '', '', '', '', '', '', '')
00024.000 24 ('', '24', '', '', '', '', '', '', '')
string: ' 8zoom8. 8.000 0008 0008. and0008.000 '
8 8 ('', '8', '', '', '', '', '', '', '')
8. 8 ('', '8', '', '', '', '', '', '', '')
8.000 8 ('', '8', '', '', '', '', '', '', '')
0008 8 ('', '8', '', '', '', '', '', '', '')
0008. 8 ('', '8', '', '', '', '', '', '', '')
0008.000 8 ('', '8', '', '', '', '', '', '', '')
string: ' 0 00000M0. = 000. 0.0 0.000 000.0 000.000 .000000 .0 '
0 0 ('', '0', '', '', '', '', '', '', '')
00000 0 ('', '0', '', '', '', '', '', '', '')
0. 0 ('', '0', '', '', '', '', '', '', '')
000. 0 ('', '0', '', '', '', '', '', '', '')
0.0 0 ('', '', '0', '', '', '', '', '', '')
0.000 0 ('', '', '0', '', '', '', '', '', '')
000.0 0 ('', '', '0', '', '', '', '', '', '')
000.000 0 ('', '', '0', '', '', '', '', '', '')
.000000 0 ('', '', '0', '', '', '', '', '', '')
.0 0 ('', '', '0', '', '', '', '', '', '')
string: ' .0000023456 .0000023456000 .0005872 .0005872000 .00503 .00503000 '
.0000023456 0.0000023456 ('', '', '', '.0000023456', '', '', '', '', '')
.0000023456000 0.0000023456 ('', '', '', '.0000023456', '', '', '', '', '')
.0005872 0.0005872 ('', '', '', '.0005872', '', '', '', '', '')
.0005872000 0.0005872 ('', '', '', '.0005872', '', '', '', '', '')
.00503 0.00503 ('', '', '', '.00503', '', '', '', '', '')
.00503000 0.00503 ('', '', '', '.00503', '', '', '', '', '')
string: ' .068 .0680000 .8 .8000 .123456123456 .123456123456000 '
.068 0.068 ('', '', '', '.068', '', '', '', '', '')
.0680000 0.068 ('', '', '', '.068', '', '', '', '', '')
.8 0.8 ('', '', '', '.8', '', '', '', '', '')
.8000 0.8 ('', '', '', '.8', '', '', '', '', '')
.123456123456 0.123456123456 ('', '', '', '.123456123456', '', '', '', '', '')
.123456123456000 0.123456123456 ('', '', '', '.123456123456', '', '', '', '', '')
string: ' .657 .657000 .45 .4500000 .7 .70000 0.0000023230000 000.0000023230000 '
.657 0.657 ('', '', '', '.657', '', '', '', '', '')
.657000 0.657 ('', '', '', '.657', '', '', '', '', '')
.45 0.45 ('', '', '', '.45', '', '', '', '', '')
.4500000 0.45 ('', '', '', '.45', '', '', '', '', '')
.7 0.7 ('', '', '', '.7', '', '', '', '', '')
.70000 0.7 ('', '', '', '.7', '', '', '', '', '')
0.0000023230000 0.000002323 ('', '', '', '.000002323', '', '', '', '', '')
000.0000023230000 0.000002323 ('', '', '', '.000002323', '', '', '', '', '')
string: ' 0.0081000 0000.0081000 0.059000 0000.059000 '
0.0081000 0.0081 ('', '', '', '.0081', '', '', '', '', '')
0000.0081000 0.0081 ('', '', '', '.0081', '', '', '', '', '')
0.059000 0.059 ('', '', '', '.059', '', '', '', '', '')
0000.059000 0.059 ('', '', '', '.059', '', '', '', '', '')
string: ' 0.78987400000 snow 00000.78987400000 0.4400000 00000.4400000 '
0.78987400000 0.789874 ('', '', '', '.789874', '', '', '', '', '')
00000.78987400000 0.789874 ('', '', '', '.789874', '', '', '', '', '')
0.4400000 0.44 ('', '', '', '.44', '', '', '', '', '')
00000.4400000 0.44 ('', '', '', '.44', '', '', '', '', '')
string: ' -0.5000 -0000.5000 0.90 000.90 0.7 000.7 '
-0.5000 -0.5 ('-', '', '', '.5', '', '', '', '', '')
-0000.5000 -0.5 ('-', '', '', '.5', '', '', '', '', '')
0.90 0.9 ('', '', '', '.9', '', '', '', '', '')
000.90 0.9 ('', '', '', '.9', '', '', '', '', '')
0.7 0.7 ('', '', '', '.7', '', '', '', '', '')
000.7 0.7 ('', '', '', '.7', '', '', '', '', '')
string: ' 2.6 00002.6 00002.60000 4.71 0004.71 0004.7100 '
2.6 2.6 ('', '', '', '', '2.6', '', '', '', '')
00002.6 2.6 ('', '', '', '', '2.6', '', '', '', '')
00002.60000 2.6 ('', '', '', '', '2.6', '', '', '', '')
4.71 4.71 ('', '', '', '', '4.71', '', '', '', '')
0004.71 4.71 ('', '', '', '', '4.71', '', '', '', '')
0004.7100 4.71 ('', '', '', '', '4.71', '', '', '', '')
string: ' 23.49 00023.49 00023.490000 103.45 0000103.45 0000103.45000 '
23.49 23.49 ('', '', '', '', '23.49', '', '', '', '')
00023.49 23.49 ('', '', '', '', '23.49', '', '', '', '')
00023.490000 23.49 ('', '', '', '', '23.49', '', '', '', '')
103.45 103.45 ('', '', '', '', '103.45', '', '', '', '')
0000103.45 103.45 ('', '', '', '', '103.45', '', '', '', '')
0000103.45000 103.45 ('', '', '', '', '103.45', '', '', '', '')
string: ' 10003.45067 000010003.45067 000010003.4506700 '
10003.45067 10003.45067 ('', '', '', '', '10003.45067', '', '', '', '')
000010003.45067 10003.45067 ('', '', '', '', '10003.45067', '', '', '', '')
000010003.4506700 10003.45067 ('', '', '', '', '10003.45067', '', '', '', '')
string: ' +15000.0012 +000015000.0012 +000015000.0012000 '
+15000.0012 +15000.0012 ('+', '', '', '', '15000.0012', '', '', '', '')
+000015000.0012 +15000.0012 ('+', '', '', '', '15000.0012', '', '', '', '')
+000015000.0012000 +15000.0012 ('+', '', '', '', '15000.0012', '', '', '', '')
string: ' 78000.89 000078000.89 000078000.89000 '
78000.89 78000.89 ('', '', '', '', '78000.89', '', '', '', '')
000078000.89 78000.89 ('', '', '', '', '78000.89', '', '', '', '')
000078000.89000 78000.89 ('', '', '', '', '78000.89', '', '', '', '')
string: ' .0457e10 .0457000e10 00000.0457000e10 '
.0457e10 0.0457e10 ('', '', '', '.0457', '', 'e', '10', '', '')
.0457000e10 0.0457e10 ('', '', '', '.0457', '', 'e', '10', '', '')
00000.0457000e10 0.0457e10 ('', '', '', '.0457', '', 'e', '10', '', '')
string: ' 258e8 2580000e4 0000000002580000e4 '
258e8 258e8 ('', '258', '', '', '', 'e', '8', '', '')
2580000e4 2580000e4 ('', '2580000', '', '', '', 'e', '4', '', '')
0000000002580000e4 2580000e4 ('', '2580000', '', '', '', 'e', '4', '', '')
string: ' 0.782e10 0000.782e10 0000.7820000e10 '
0.782e10 0.782e10 ('', '', '', '.782', '', 'e', '10', '', '')
0000.782e10 0.782e10 ('', '', '', '.782', '', 'e', '10', '', '')
0000.7820000e10 0.782e10 ('', '', '', '.782', '', 'e', '10', '', '')
string: ' 1.23E2 0001.23E2 0001.2300000E2 '
1.23E2 1.23E2 ('', '', '', '', '1.23', 'E', '2', '', '')
0001.23E2 1.23E2 ('', '', '', '', '1.23', 'E', '2', '', '')
0001.2300000E2 1.23E2 ('', '', '', '', '1.23', 'E', '2', '', '')
string: ' 432e-102 0000432e-102 004320000e-106 '
432e-102 432e-102 ('', '432', '', '', '', 'e-', '102', '', '')
0000432e-102 432e-102 ('', '432', '', '', '', 'e-', '102', '', '')
004320000e-106 4320000e-106 ('', '4320000', '', '', '', 'e-', '106', '', '')
string: ' 1.46e10and0001.46e10 0001.4600000e10 '
1.46e10 1.46e10 ('', '', '', '', '1.46', 'e', '10', '', '')
0001.46e10 1.46e10 ('', '', '', '', '1.46', 'e', '10', '', '')
0001.4600000e10 1.46e10 ('', '', '', '', '1.46', 'e', '10', '', '')
string: ' 1.077e-300 0001.077e-300 0001.077000e-300 '
1.077e-300 1.077e-300 ('', '', '', '', '1.077', 'e-', '300', '', '')
0001.077e-300 1.077e-300 ('', '', '', '', '1.077', 'e-', '300', '', '')
0001.077000e-300 1.077e-300 ('', '', '', '', '1.077', 'e-', '300', '', '')
string: ' 1.069e10 0001.069e10 0001.069000e10 '
1.069e10 1.069e10 ('', '', '', '', '1.069', 'e', '10', '', '')
0001.069e10 1.069e10 ('', '', '', '', '1.069', 'e', '10', '', '')
0001.069000e10 1.069e10 ('', '', '', '', '1.069', 'e', '10', '', '')
string: ' 105040.03e10 000105040.03e10 105040.0300e10 '
105040.03e10 105040.03e10 ('', '', '', '', '105040.03', 'e', '10', '', '')
000105040.03e10 105040.03e10 ('', '', '', '', '105040.03', 'e', '10', '', '')
105040.0300e10 105040.03e10 ('', '', '', '', '105040.03', 'e', '10', '', '')
string: ' +286E000024.487900 -78.4500e.14500 .0140E789. '
+286E000024.487900 +286E24.4879 ('+', '286', '', '', '', 'E', '', '', '24.4879')
-78.4500e.14500 -78.45e0.145 ('-', '', '', '', '78.45', 'e', '', '.145', '')
.0140E789. 0.014E789 ('', '', '', '.014', '', 'E', '789', '', '')
string: ' 081,12.40E07,95.0120 0045,78,123.03500e-0.00 '
081,12.40E07,95.0120 81,12.4E7,95.012 ('', '', '', '', '81,12.4', 'E', '', '', '7,95.012')
0045,78,123.03500 45,78,123.035 ('', '', '', '', '45,78,123.035', '', '', '', '')
string: ' 0096,78,473.0380e-0. 0008,78,373.066000E0. 0004512300.E0000 '
0096,78,473.0380 96,78,473.038 ('', '', '', '', '96,78,473.038', '', '', '', '')
0008,78,373.066000 8,78,373.066 ('', '', '', '', '8,78,373.066', '', '', '', '')
0004512300. 4512300 ('', '4512300', '', '', '', '', '', '', '')
string: ' ..18000 25..00 36...77 2..8 '
No match, No catched string, No groups.
string: ' 3.8..9 .12500. 12.51.400 '
No match, No catched string, No groups.
string: ' 00099,111.8713000 -0012,45,83,987.26+0.000,099,88,44.or00,00,00.00must'
00099,111.8713000 99,111.8713 ('', '', '', '', '99,111.8713', '', '', '', '')
-0012,45,83,987.26 -12,45,83,987.26 ('-', '', '', '', '12,45,83,987.26', '', '', '', '')
00,00,00.00 0 ('', '', '0', '', '', '', '', '', '')
string: ' 00099,44,and 0000,099,88,44.bom'
00099,44, 99,44 ('', '99,44', '', '', '', '', '', '', '')
0000,099,88,44. 99,88,44 ('', '99,88,44', '', '', '', '', '', '', '')
string: '00,000,00.587000 77,98,23,45., this,that '
00,000,00.587000 0.587 ('', '', '', '.587', '', '', '', '', '')
77,98,23,45. 77,98,23,45 ('', '77,98,23,45', '', '', '', '', '', '', '')
string: ' ,111 145.20 +9,9,9 0012800 .,,. 1 100,000 '
,111 111 ('', '111', '', '', '', '', '', '', '')
145.20 145.2 ('', '', '', '', '145.2', '', '', '', '')
+9,9,9 +9,9,9 ('+', '9,9,9', '', '', '', '', '', '', '')
0012800 12800 ('', '12800', '', '', '', '', '', '', '')
1 1 ('', '1', '', '', '', '', '', '', '')
100,000 100,000 ('', '100,000', '', '', '', '', '', '', '')
string: '1,1,1.111 000,001.111 -999. 0. 111.110000 1.1.1.111 9.909,888'
1,1,1.111 1,1,1.111 ('', '', '', '', '1,1,1.111', '', '', '', '')
000,001.111 1.111 ('', '', '', '', '1.111', '', '', '', '')
-999. -999 ('-', '999', '', '', '', '', '', '', '')
0. 0 ('', '0', '', '', '', '', '', '', '')
111.110000 111.11 ('', '', '', '', '111.11', '', '', '', '')
.,.,.
或9,9,9,9
或9,9.99.9
这样的格式。这些正则表达式不会要求数字以正确的格式输入,最糟糕的是将标点符号视为数字。还有一些可选的微调(例如是否允许前导和尾随零),但我看到的一些答案是绝对错误的。我真的不喜欢投反对票,尤其是在诚实尝试时,但我觉得这里的答案需要整理。这是一个常见的问题,肯定会再次被问到。 - Justin Morgan