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How do I get the row count of a pandas DataFrame?
...[0].count()", "len(data.index)"],
xlabel="data rows"
)
EDIT: As @Dan Allen noted in the comments len(df.index) and df[0].count() are not interchangeable as count excludes NaNs,
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How do I create a copy of an object in PHP?
...ass by reference is a bad idea, because it makes the effect of a function call depend on the implementation of the function, rather than on the specification. It's got nothing to do with pass by value being the default.
– Oswald
Oct 4 '13 at 7:06
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Passing parameters to addTarget:action:forControlEvents
...wsDetails: method here. You just create a selector to make button able to call it when certain action occurs (touch up in your case). Controls can use 3 types of selectors to respond to actions, all of them have predefined meaning of their parameters:
with no parameters
action:@selector(switchToN...
Where do the Python unit tests go?
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For a file module.py, the unit test should normally be called test_module.py, following Pythonic naming conventions.
There are several commonly accepted places to put test_module.py:
In the same directory as module.py.
In ../tests/test_module.py (at the same level as t...
Javascript - Append HTML to container element without innerHTML
...;
font-size: 30px;
outline: none;
padding: 0 20px;
transition: all .3s;
}
button:hover {
background: rgba(7, 99, 53, 1);
color: rgba(255,255,255,1);
}
p {
font-size: 20px;
font-weight: bold;
}
<button type="button" onclick="addChild()">Append Child</button>
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specify project file of a solution using msbuild
...and ')' with '_' in the folder name (GYP generated projects). I guess it's all the special characters are replaced with underscore.
– Maxime Viargues
Jun 13 '16 at 1:49
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C++ Redefinition Header Files (winsock2.h)
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I'm not including <windows.h> at all, I know <winsock2.h> does its for me.
– akif
Sep 3 '09 at 11:26
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Why does ++[[]][+[]]+[+[]] return the string “10”?
...array ([]). Due to references it's wrong to say [[]][0] === [], but let's call the inner array A to avoid the wrong notation.
++ before its operand means “increment by one and return the incremented result”. So ++[[]][0] is equivalent to Number(A) + 1 (or +A + 1).
Again, we can simplify the me...
css中@media screen and (-webkit-min-device-pixel-ratio:0)解析 - 更多技...
... { Selector { property: value; } }
上面写法主要是针对Webkit内核的浏览器，如Google Chrome 和 Safari浏览器。css media screen
Count number of records returned by group by
...his to DISTINCT COUNT() OVER(), and the query performance improved dramatically.
– Joe Aldrich
Sep 20 '17 at 13:33
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