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How do you match only valid roman numerals with a regular expression?
...mple:
0: <empty> matched by M{0}
1000: M matched by M{1}
2000: MM matched by M{2}
3000: MMM matched by M{3}
4000: MMMM matched by M{4}
You could, of course, use something like M* to allow any number (including zero) of thousands, if you want to allow bigger numbers...
Is there common street addresses database design for all addresses of the world? [closed]
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12 Answers
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When should I use nil and NULL in Objective-C?
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edited Jan 27 '16 at 14:15
community wiki
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Bytes of a string in Java
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291
A string is a list of characters (i.e. code points). The number of bytes taken to represent t...
JavaScript Regular Expression Email Validation [duplicate]
...ine it as a regular expression:
var pattern = /^\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}$/;
BTW, please don't validate email addresses on the client-side. Your regular expression is way too simple to pass for a solid implementation anyway.
See the real thing here: http://www.ex-parrot.com/~pdw/Mail-RFC...
Should all Python classes extend object?
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In Python 2, not inheriting from object will create an old-style class, which, amongst other effects, causes type to give different results:
>>> class Foo: pass
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>>> type(Foo())
<type 'instance'>
vs.
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What does `kill -0 $pid` in a shell script do?
... then no signal is sent, but error checking is still performed.
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kill(2)
$ man 2 kill
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If sig is 0, then no signal is sent, but error checking is still performed; this
can be used to check for the existence of a process ID or process group ID.
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Can grep show only words that match search pattern?
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Dan MidwoodDan Midwood
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Convert tuple to list and back
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298
Convert tuple to list:
>>> t = ('my', 'name', 'is', 'mr', 'tuple')
>>> t
('...