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From inside of a Docker container, how do I connect to the localhost of the machine?
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How to drop rows of Pandas DataFrame whose value in a certain column is NaN
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AMC
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answered Nov 16 '12 at 9:34
eumiroeumiro
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Why is it slower to iterate over a small string than a small list?
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TL;DR
The actual speed difference is closer to 70% (or more) once a lot of the overhead is removed, for Python 2.
Object creation is not at fault. Neither method creates a new object, as one-character strings are cached.
The difference is unobvious, but is likely created f...
How to access the ith column of a NumPy multidimensional array?
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>>> test[:,0]
array([1, 3, 5])
Similarly,
>>> test[1,:]
array([3, 4])
lets you access rows. This is covered in Section 1.4 (Indexing) of the NumPy reference. This is quick, at least in my experience. It's certainly muc...
Null vs. False vs. 0 in PHP
...developers can spot/utilize the difference between Null and False and 0 and all the other good "nothing" entities.
What is the difference, specifically in PHP? Does it have something to do with === ?
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How to check if hex color is “too black”?
...Int(c, 16); // convert rrggbb to decimal
var r = (rgb >> 16) & 0xff; // extract red
var g = (rgb >> 8) & 0xff; // extract green
var b = (rgb >> 0) & 0xff; // extract blue
var luma = 0.2126 * r + 0.7152 * g + 0.0722 * b; // per ITU-R BT.709
if (luma < 40) {
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I do not want to inherit the child opacity from the parent in CSS
...e 'a' is the level of transparency.
So instead of:
background-color: rgb(0,0,255); opacity: 0.5;
use
background-color: rgba(0,0,255,0.5);
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What's the point of malloc(0)?
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According to the specifications, malloc(0) will return either "a null pointer or a unique pointer that can be successfully passed to free()".
This basically lets you allocate nothing, but still pass the "artist" variable to a call to free() without worry. For pra...
RegEx to parse or validate Base64 data
...sion to match Base64 encoded words, you can use the following:
^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$
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Fastest hash for non-cryptographic uses?
...because of the reduced length (32 bits compared to 128 bits respectively 160 bits). But if you just want to check whether a stored string is corrupted, you'll be fine with CRC32.
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