当我使用-V开关查询ssh.exe时，我得到的字符串看起来像这样：
OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.4
我需要一个仅返回“ 7.7”的正则表达式过滤器。问题是我不知道在版本号之前或之后会出现什么文本，因此我试图只返回“数字，点和数字”，但我不知道如何首先隔离该文本。实例（7.7），而忽略第二个实例（2.4.6）。
除了匹配太多实例外，它还可以工作：
\d\.\d
那么，我将如何修改它以忽略多余的文本？
谢谢。
答案 0 :(得分：2)
您必须在正则表达式中删除全局属性。像这样：
/\d\.\d/
不是这样的：
/\d\.\d/g
答案 1 :(得分：1)
您可以使用否定的超前查询来检查第二个数字后是否有一个点
^(\w+)(\d{1,2}\.\d{1,2})(?!\.)
在我的情况下，我使用起始字符串字符^，然后多次使用任何单词（(\w+)）。然后，我使用正则表达式的下一部分来确保只有一个或两个数字用点分隔。 （(\d{1,2}\.\d{1,2})），然后我们检查之后是否没有点（(?!\.)）。
正则表达式的完全匹配将从字符串开头返回版本，但是您可以使用捕获组来隔离版本。
如果您想测试更多案例，我已经创建了regex101.com。
答案 2 :(得分：0)
您可以使用lookbehind在开头处仅考虑structure(list(INVOICE_DT = c("2016-01-29", "2016-01-29", "2016-01-29",
"2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29",
"2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29",
"2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29",
"2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29",
"2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29", "2016-01-29",
"2016-01-29", "2016-01-29"), BRANCH_CODE = c("AK001", "AK001",
"AK001", "AK001", "AK001", "AK001", "AK001", "AK001", "AK001",
"AK001", "AK001", "AK001", "AK001", "AK001", "AK001", "AK001",
"AK001", "AK001", "AK001", "AK001", "AK001", "AK001", "AK001",
"AK001", "AK001", "AK001", "AK001", "AK001", "AK001", "AK001"
), INVOICE_NO = c("AK0015522", "AK0015529", "AK0015515", "AK0015529",
"AK0015514", "AK0015513", "AK0015519", "AK0015519", "AK0015520",
"AK0015520", "AK0015520", "AK0015522", "AK0015520", "AK0015520",
"AK0015520", "AK0015518", "AK0015525", "AK0015520", "AK0015519",
"AK0015520", "AK0015525", "AK0015518", "AK0015529", "AK0015519",
"AK0015525", "AK0015519", "AK0015519", "AK0015522", "AK0015522",
"AK0015529"), INV_SEQ_NO = c(6L, 6L, 3L, 3L, 3L, 3L, 148L, 149L,
91L, 45L, 162L, 34L, 125L, 39L, 159L, 56L, 64L, 127L, 160L, 93L,
45L, 34L, 5L, 138L, 46L, 38L, 161L, 35L, 28L, 4L), INV_ITEM_ID = c("11239190",
"11239190", "55692", "400050-131280", "0700535", "0800758", "69970",
"0445050", "0819092", "0115160", "0115160", "0703316", "55692",
"0115157", "0115157", "0115157", "440704-131280", "55618", "0703318",
"0205428", "0702119", "0115157", "465278", "465278", "0702121",
"15166", "0703315", "0703315", "0715718", "0243945"), ITEM_DESCR = c("Au-Ve-Co# 20898",
"Au-Ve-Co# 20898", "MM HSS T TAP 16X1.5", "3/16\"\"\"\"H05703-100R Hs",
"18/2 BLK SOOW", "3x1x1/4 180G FW", "BF SPEC SER HV1-6C", "1/4MP External Seat",
"1-1/2xNHConditonDisc", "HCS 7/16-14x1 3/4 YZ8", "HCS 7/16-14x1 3/4 YZ8",
"25AMP MINI AUTO FUSE", "MM HSS T TAP 16X1.5", "HCS 7/16-14x1.25 YZ8",
"HCS 7/16-14x1.25 YZ8", "HCS 7/16-14x1.25 YZ8", "BPOLY MELBW 1/4TX1/8",
"MM HSS P TAP 5 X 0.8", "MAXI-BLADE 20 AMP", "1-1/2\"\"\"\" T3 VF SURF",
"16ga Red Wire/PPF", "HCS 7/16-14x1.25 YZ8", "80I 45 ELBOW 1/4 BLK",
"80I 45 ELBOW 1/4 BLK", "16ga Blk Wire/PPF", "HCS 7/16-14x3.25 YZ8",
"20AMP MINI AUTO FUSE", "20AMP MINI AUTO FUSE", "3/0-3/8\"\"\"\"HvyWalCprLug",
"97053 Pink Marker"), STD_ITEM = c("Y", "Y", "Y", "Y", "Y", "Y",
"Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y",
"Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y", "Y"), PRIVATE_LABEL = c("N",
"N", "Y", "N", "N", "N", "N", "N", "N", "N", "N", "N", "Y", "N",
"N", "N", "N", "Y", "N", "N", "N", "N", "Y", "Y", "N", "N", "N",
"N", "N", "N"), CATEGORY_PATH1 = c("08.5-Fleet & Automotive",
"08.5-Fleet & Automotive", "07-Cutting Tools & Metalworking",
"08-Hydraulics & Pneumatics", "09-Electrical", "05-Abrasives",
"08-Hydraulics & Pneumatics", "07.3-Plumbing", "05-Abrasives",
"01-Fasteners", "01-Fasteners", "08.5-Fleet & Automotive", "07-Cutting Tools & Metalworking",
"01-Fasteners", "01-Fasteners", "01-Fasteners", "08-Hydraulics & Pneumatics",
"07-Cutting Tools & Metalworking", "08.5-Fleet & Automotive",
"05-Abrasives", "08.5-Fleet & Automotive", "01-Fasteners", "07.3-Plumbing",
"07.3-Plumbing", "08.5-Fleet & Automotive", "01-Fasteners", "08.5-Fleet & Automotive",
"08.5-Fleet & Automotive", "08.5-Fleet & Automotive", "11-Chemicals & Paints"
), CATEGORY_PATH2 = c("03-Batteries & Accessories", "03-Batteries & Accessories",
"04-Threading and Tapping", "02-Hose and Hose Reels", "05-Electrical Wire and Accessories",
"03-Coated and Non-Woven Abrasives", "07-Valves & Accessories",
"04-Valves & Valve Accessories", "03-Coated and Non-Woven Abrasives",
"01-Bolts", "01-Bolts", "02-Fleet Electrical Products", "04-Threading and Tapping",
"01-Bolts", "01-Bolts", "01-Bolts", "01-Fittings", "04-Threading and Tapping",
"02-Fleet Electrical Products", "03-Coated and Non-Woven Abrasives",
"02-Fleet Electrical Products", "01-Bolts", "01-Pipe Fittings",
"01-Pipe Fittings", "02-Fleet Electrical Products", "01-Bolts",
"02-Fleet Electrical Products", "02-Fleet Electrical Products",
"02-Fleet Electrical Products", "11-Paints, Marking, and Accessories"
), CUST_ID = c("AK0010001", "AK0010001", "AK0010001", "AK0010001",
"AK0010001", "AK0010001", "AK0010001", "AK0010001", "AK0010001",
"AK0010001", "AK0010001", "AK0010001", "AK0010001", "AK0010001",
"AK0010001", "AK0010001", "AK0010001", "AK0010001", "AK0010001",
"AK0010001", "AK0010001", "AK0010001", "AK0010001", "AK0010001",
"AK0010001", "AK0010001", "AK0010001", "AK0010001", "AK0010001",
"AK0010001"), CUSTOMER_TIER = c("Tier 3", "Tier 3", "Tier 3",
"Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3",
"Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3",
"Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3",
"Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3", "Tier 3"),
IS_VENDING = c("No", "No", "No", "No", "No", "No", "No",
"No", "No", "No", "No", "No", "No", "No", "No", "No", "No",
"No", "No", "No", "No", "No", "No", "No", "No", "No", "No",
"No", "No", "No"), SALE_PRICE = c(10.53, 10.53, 23.0175,
2.0251, 0.4755, 6.4725, 15.8235, 1.468, 1.0275, 0.3425, 0.3425,
0.3726, 23.0175, 0.2513, 0.2513, 0.2513, 2.7412, 5.7675,
2.226, 1.5579, 0.1418, 0.2513, 12.0835, 12.0835, 0.1297,
0.625, 0.3726, 0.3726, 3.514, 4.1112), TOTAL_COST = c(6.877449,
6.877449, 9.399562, 0.924873, 0.245128, 2.953287, 6.227787,
0.703494, 0.52035, 0.083454, 0.083454, 0.134285, 9.399562,
0.062686, 0.062686, 0.062686, 1.3493, 2.386274, 0.77503,
0.524996, 0.051595, 0.062686, 4.47782, 4.47782, 0.051628,
0.164998, 0.125893, 0.125893, 2.183983, 1.469989), POS_COST = c(6.877449,
6.877449, 9.399562, 0.924873, 0.245128, 2.953287, 6.227787,
0.703494, 0.52035, 0.083454, 0.083454, 0.134285, 9.399562,
0.062686, 0.062686, 0.062686, 1.3493, 2.386274, 0.77503,
0.524996, 0.051595, 0.062686, 4.47782, 4.47782, 0.051628,
0.164998, 0.125893, 0.125893, 2.183983, 1.469989), CE100 = c(6.55,
6.55, 9.25, 0.95, 0.23785, 2.81, 5.93127, 1.17, 0.508, 0.074946,
0.074946, 0.12, 9.25, 0.058626, 0.058626, 0.058626, 1.31,
2.35, 0.61, 0.5, 0.05172, 0.058626, 4.2844, 4.2844, 0.05172,
0.12255, 0.12, 0.12, 2.08, 1.43), CE110 = c(NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_), CE120 = c(NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_), CE200 = c(0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0), CORP_PRICE = c(NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,
NA_real_, NA_real_, NA_real_, NA_real_), QTY_SOLD = c(15L,
10L, 6L, 50L, 250L, 10L, 10L, 20L, 50L, 25L, 25L, 50L, 6L,
25L, 25L, 25L, 10L, 6L, 10L, 30L, 100L, 25L, 15L, 10L, 100L,
20L, 50L, 50L, 4L, 36L), PACKSLIP_WHSL = c(NA, NA, 30.69,
2.63, 0.7315, 8.63, 20.55, 1.96, 1.37, 0.685, 0.685, 0.5323,
30.69, 0.5025, 0.5025, 0.5025, 3.56, 7.69, 3.18, 1.82, 0.2145,
0.5025, 18.59, 18.59, 0.1961, 1.25, 0.5323, 0.5323, 5.02,
5.71), PRICING_GROUP = c("PGB", "PGB", "PGB", "PGB", "PGB",
"PGB", "PGG", "PGB", "PGB", "PGB", "PGB", "PGB", "PGB", "PGB",
"PGB", "PGB", "PGB", "PGB", "PGB", "PGB", "PGB", "PGB", "PGB",
"PGB", "PGB", "PGB", "PGB", "PGB", "PGB", "PGB"), PGG_MIN_PRICE = c(257.9043375,
171.936225, 184.14, 131.5, 175.56, 86.3, 154.125, 39.2, 68.5,
15.07, 15.07, 26.615, 184.14, 11.055, 11.055, 11.055, 35.6,
46.14, 31.8, 54.6, 21.45, 11.055, 253.7535, 185.9, 19.61,
22, 26.615, 26.615, 20.08, 205.56), PGY_MIN_PRICE = c(206.32347,
137.54898, 171.2502, 128.87, 170.07375, 80.259, 147.96, 36.456,
63.705, 13.3575, 13.3575, 24.75195, 171.2502, 9.79875, 9.79875,
9.79875, 33.108, 45.2172, 29.574, 50.778, 19.9485, 9.79875,
245.388, 163.592, 18.2373, 19.5, 24.75195, 24.75195, 18.6744,
191.1708), PGR_MIN_PRICE = c(171.936225, 114.62415, 162.0432,
124.925, 166.41625, 75.944, 141.795, 35.672, 60.28, 9.9325,
9.9325, 24.21965, 162.0432, 7.28625, 7.28625, 7.28625, 32.396,
43.833, 28.938, 48.048, 19.5195, 7.28625, 239.811, 159.874,
17.8451, 14.5, 24.21965, 24.21965, 18.2728, 180.8928), `Ext Sale` = c(157.95,
105.3, 138.105, 101.255, 118.875, 64.725, 158.235, 29.36,
51.375, 8.5625, 8.5625, 18.63, 138.105, 6.2825, 6.2825, 6.2825,
27.412, 34.605, 22.26, 46.737, 14.18, 6.2825, 181.2525, 120.835,
12.97, 12.5, 18.63, 18.63, 14.056, 148.0032), `Ext Total Cost` = c(103.161735,
68.77449, 56.397372, 46.24365, 61.282, 29.53287, 62.27787,
14.06988, 26.0175, 2.08635, 2.08635, 6.71425, 56.397372,
1.56715, 1.56715, 1.56715, 13.493, 14.317644, 7.7503, 15.74988,
5.1595, 1.56715, 67.1673, 44.7782, 5.1628, 3.29996, 6.29465,
6.29465, 8.735932, 52.919604), cust_part = c("AK001000111239190",
"AK001000111239190", "AK001000155692", "AK0010001400050-131280",
"AK00100010700535", "AK00100010800758", "AK001000169970",
"AK00100010445050", "AK00100010819092", "AK00100010115160",
"AK00100010115160", "AK00100010703316", "AK001000155692",
"AK00100010115157", "AK00100010115157", "AK00100010115157",
"AK0010001440704-131280", "AK001000155618", "AK00100010703318",
"AK00100010205428", "AK00100010702119", "AK00100010115157",
"AK0010001465278", "AK0010001465278", "AK00100010702121",
"AK001000115166", "AK00100010703315", "AK00100010703315",
"AK00100010715718", "AK00100010243945")), .Names = c("INVOICE_DT",
"BRANCH_CODE", "INVOICE_NO", "INV_SEQ_NO", "INV_ITEM_ID", "ITEM_DESCR",
"STD_ITEM", "PRIVATE_LABEL", "CATEGORY_PATH1", "CATEGORY_PATH2",
"CUST_ID", "CUSTOMER_TIER", "IS_VENDING", "SALE_PRICE", "TOTAL_COST",
"POS_COST", "CE100", "CE110", "CE120", "CE200", "CORP_PRICE",
"QTY_SOLD", "PACKSLIP_WHSL", "PRICING_GROUP", "PGG_MIN_PRICE",
"PGY_MIN_PRICE", "PGR_MIN_PRICE", "Ext Sale", "Ext Total Cost",
"cust_part"), .internal.selfref = <pointer: (nil)>, row.names = c(NA,
30L), class = c("data.table", "data.frame"))
中的一个：
_答案 3 :(得分：0)
您可以从字符串for error in language:
if len(error.suggest())>0:
correction = error.suggest()[0]
error.replace("%s" %(correction))
的开头匹配大写，小写或下划线^，然后在捕获组中捕获数字[a-zA-Z_]+的模式。