大约有 40,000 项符合查询结果（耗时：0.1300秒） [XML]
What's the difference between an id and a class?
... to a specific element and class when you have a number of things that are all alike. For instance, common id elements are things like header, footer, sidebar. Common class elements are things like highlight or external-link.
It's a good idea to read up on the cascade and understand the precedence ...
Get query from java.sql.PreparedStatement [duplicate]
...re lucky, the JDBC driver in question may return the complete SQL by just calling PreparedStatement#toString(). I.e.
System.out.println(preparedStatement);
To my experience, the ones which do so are at least the PostgreSQL 8.x and MySQL 5.x JDBC drivers. For the case your JDBC driver doesn't supp...
What's the best way to check if a file exists in C?
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There are pitfalls associated with access(). There is a TOCTOU (time of check, time of use) window of vulnerability between using access() and whatever else you do afterwards. [...to be continued...]
– Jonathan Leff...
What Regex would capture everything from ' mark to the end of a line?
...but not include it in the output, you would use:
(?<=').*$
This basically says give me all characters that follow the ' char until the end of the line.
Edit: It has been noted that $ is implicit when using .* and therefore not strictly required, therefore the pattern:
'.*
is technically c...
How to set working/current directory in Vim?
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@falstro, do you know how :cd command can apply to all windows within the same vim running instances? Ex: when using split :sp
– mgouin
Jan 19 '17 at 21:29
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Check if list contains any of another list
...ould be to project parameters to source and then use Intersect which internally uses a HashSet<T> so instead of O(n^2) for the first approach (the equivalent of two nested loops) you can do the check in O(n) :
bool hasMatch = parameters.Select(x => x.source)
.Inte...
postgresql - add boolean column to table set default
...D COLUMN priv_user BOOLEAN;, then UPDATE users SET priv_user = 'f'; and finally if you need to ALTER TABLE users ALTER COLUMN priv_user SET NOT NULL;.
– Craig Ringer
Aug 14 '12 at 0:19
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DateTime.Now vs. DateTime.UtcNow
...f how the two properties work. I know the second one is universal and basically doesn't deal with time zones, but can someone explain in detail how they work and which one should be used in what scenario?
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Passing a function with parameters as a parameter?
...nction wrapper that knows about the parameter and passes it to the actual callback implementation.
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Take the content of a list and append it to another list
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Take a look at itertools.chain for a fast way to treat many small lists as a single big list (or at least as a single big iterable) without copying the smaller lists:
>>> import itertools
>>> p = ['a', 'b', 'c']
>>> q = ['d', 'e', 'f']
>>> r = ['g', ...