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Pure virtual function with implementation
...tation. A derived class can explicitly call the base class implementation (if access permissions allow it) by using a fully-scoped name (by calling A::f() in your example - if A::f() were public or protected). Something like:
class B : public A {
virtual void f() {
// class B doesn't ...
Should I embed images as data/base64 in CSS or HTML
...page or style sheet get loaded.
Base64 encoding bloats image sizes by 33%.
If served in a gzipped resource, data: images are almost certainly going to be a terrible strain on the server's resources! Images are traditionally very CPU intensive to compress, with very little reduction in size.
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Pandas - Get first row value of a given column
...could use:
In [30]: df_test['Btime'].iloc[0]
Out[30]: 1.2
There is a difference between df_test['Btime'].iloc[0] (recommended) and df_test.iloc[0]['Btime']:
DataFrames store data in column-based blocks (where each block has a single
dtype). If you select by column first, a view can be returned...
Read a file one line at a time in node.js?
...);
});
The last line is read correctly (as of Node v0.12 or later), even if there is no final \n.
UPDATE: this example has been added to Node's API official documentation.
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In which order do CSS stylesheets override?
....w3.org/TR/2011/REC-CSS2-20110607/cascade.html#cascade
In short: more specific rules override more general ones. Specificity is defined based on how many IDs, classes, and element names are involved, as well as whether the !important declaration was used. When multiple rules of the same "specificit...
Principal component analysis in Python
...o 90 %, 95 % ...
p.npc: number of principal components,
e.g. 2 if the top 2 eigenvalues are >= `fraction` of the total.
It's ok to change this; methods use the current value.
Methods:
The methods of class PCA transform vectors or arrays of e.g.
20 variables, 2 princip...
SyntaxError: Non-ASCII character '\xa3' in file when function returns '£'
... also define encodings on a string by string basis in your code. However, if you are trying to put the pound sign literal in to your code, you'll need an encoding that supports it for the entire file.
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Total number of items defined in an enum
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System.Enum.GetNames, if you aren't already including the System namespace.
– Brett Pennings
Feb 3 '15 at 2:55
5
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What is the difference between `new Object()` and object literal notation?
What is the difference between this constructor-based syntax for creating an object:
11 Answers
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Undo part of unstaged changes in git
... can use git checkout -p, which lets you choose individual hunks from the diff between your working copy and index to revert. Likewise, git add -p allows you to choose hunks to add to the index, and git reset -p allows you to choose individual hunks from the diff between the index and HEAD to back o...