大约有 42,000 项符合查询结果(耗时:0.0878秒) [XML]

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simulate background-size:cover on or

...r a while, but I came across a great solution that doesn't use any script, and can achieve a perfect cover simulation on video with 5 lines of CSS (9 if you count selectors and brackets). This has 0 edge-cases in which it doesn't work perfectly, short of CSS3-compatibility. You can see an example h...
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How do negative margins in CSS work and why is (margin-top:-5 != margin-bottom:5)?

... Negative margins are valid in css and understanding their (compliant) behaviour is mainly based on the box model and margin collapsing. While certain scenarios are more complex, a lot of common mistakes can be avoided after studying the spec. For instance, r...
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“You have mail” message in terminal, os X [closed]

...ably it is some message from your system. Type in terminal: man mail , and see how can you get this message from your system. share | improve this answer | follow ...
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Semicolon before self-invoking function? [duplicate]

... function in JavaScript? I saw this approach in few popular jQuery plugins and I'm curious to find if this is the next awesome thing in JavaScript that I don't know. ...
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How to append rows to an R data frame

...rs of the type you want for each column, insert values into those vectors, and then, at the end, create your data.frame. Continuing with Julian's f3 (a preallocated data.frame) as the fastest option so far, defined as: # pre-allocate space f3 <- function(n){ df <- data.frame(x = numeric(n)...
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Python unittest - opposite of assertRaises?

...r test must exit with a failure condition, not an error one. On the other hand, if in running the same code you would raise a KeyError, that would be an error, not a failure. In python - differently than some other languages - Exceptions are routinely used for control flow, this is why we have the e...
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Tab key == 4 spaces and auto-indent after curly braces in Vim

...use tabs (converting spaces to tabs, bad!), makes the tab key == 4 spaces, and automatically indent code after curly brace blocks like Emacs does? ...
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Find out how much memory is being used by an object in Python [duplicate]

...ject. One of the problems you may find is that Python objects - like lists and dicts - may have references to other python objects (in this case, what would your size be? The size containing the size of each object or not?). There are some pointers overhead and internal structures related to object ...
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“Unable to find remote helper for 'https'” during git clone

...led when you compile git can cause this. If you install (lib)curl-devel, and then rebuild/install git, this should solve the problem: $ yum install curl-devel $ # cd to wherever the source for git is $ cd /usr/local/src/git-1.7.9 $ ./configure $ make $ make install This worked for me on Cento...
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How can I measure the speed of code written in PHP? [closed]

... two solutions : The quite "naïve" one is using microtime(true) tobefore and after a portion of code, to get how much time has passed during its execution ; other answers said that and gave examples already, so I won"t say much more. This is a nice solution if you want to benchmark a couple of in...