大约有 32,000 项符合查询结果（耗时：0.0644秒） [XML]
Validating IPv4 addresses with regexp
...idation, but without much luck. It seemed at one point I had had it with (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?(\.|$)){4} , but it produces some strange results:
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How to get row from R data.frame
...is, for example:
#Add your data
x <- structure(list(A = c(5, 3.5, 3.25, 4.25, 1.5 ),
B = c(4.25, 4, 4, 4.5, 4.5 ),
C = c(4.5, 2.5, 4, 2.25, 3 )
),
.Names = c("A", "B", "C"),
class = "da...
Regular expression that matches valid IPv6 addresses
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254
I was unable to get @Factor Mystic's answer to work with POSIX regular expressions, so I wrote...
PostgreSQL database default location on Linux
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answered Nov 25 '17 at 23:02
Roby SottiniRoby Sottini
1,42822 gold badges2828 silver badges5454 bronze badges
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Rank function in MySQL
...rchar(20), age int, gender char(1));
INSERT INTO person VALUES (1, 'Bob', 25, 'M');
INSERT INTO person VALUES (2, 'Jane', 20, 'F');
INSERT INTO person VALUES (3, 'Jack', 30, 'M');
INSERT INTO person VALUES (4, 'Bill', 32, 'M');
INSERT INTO person VALUES (5, 'Nick', 22, 'M');
INSERT INTO person VALU...
What is the best regular expression to check if a string is a valid URL?
...(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|::(?:[0-9a-f]{1,4}:){5}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]...
How to make code wait while calling asynchronous calls like Ajax [duplicate]
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answered Dec 25 '12 at 14:31
DogbertDogbert
181k3434 gold badges316316 silver badges332332 bronze badges
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Best way to handle list.index(might-not-exist) in python?
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edited Jan 25 '10 at 14:32
answered Jan 25 '10 at 14:02
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When should null values of Boolean be used?
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answered Jun 25 '12 at 7:53
JB NizetJB Nizet
613k7878 gold badges10641064 silver badges11381138 bronze badges
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How can I get every nth item from a List?
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answered Mar 25 '09 at 17:33
mqpmqp
61.6k1313 gold badges8888 silver badges122122 bronze badges
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