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pandas GroupBy columns with NaN (missing) values

...n the Missing Data section of the docs: NA groups in GroupBy are automatically excluded. This behavior is consistent with R, for example. One workaround is to use a placeholder before doing the groupby (e.g. -1): In [11]: df.fillna(-1) Out[11]: a b 0 1 4 1 2 -1 2 3 6 In [12]: df.fil...
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Add a new item to a dictionary in Python [duplicate]

... default_data['item3'] = 3 Easy as py. Another possible solution: default_data.update({'item3': 3}) which is nice if you want to insert multiple items at once. ...
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Sorting a tab delimited file

...u probably want sort -k4nr file.txt to sort file.txt by column 4 numerically in reverse order. (Though the data in the question has even 5 fields so the last field would be index 5.) share | impr...
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Can an Option in a Select tag carry multiple values?

... I was actually wondering this today, and I achieved it by using the php explode function, like this: HTML Form (in a file I named 'doublevalue.php': <form name="car_form" method="post" action="doublevalue_action.php"> ...
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How do I enter RGB values into Interface Builder?

... Interface Builder? I can select predefined colors but I would like to manually enter in RGB values. Where can I do this? 5...
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'UserControl' constructor with parameters in C#

Call me crazy, but I'm the type of guy that likes constructors with parameters (if needed), as opposed to a constructor with no parameters followed by setting properties. My thought process: if the properties are required to actually construct the object, they should go in the constructor. I get two...
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What's the difference between ContentControl and ContentPresenter?

...l (and vice-versa). At the moment, I'm using ContentControl pretty much all the time in my DataTemplate s. When would ContentPresenter be a better choice? and why? ...
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Hiding the scroll bar on an HTML page

... Actually, this is not completely the right answer : overflow:hidden doesn't "hide" the scrollbar. It also stop scrolling feature on the page. That's not exactly what we ask for. – adriendenat ...
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Does Go have “if x in” construct similar to Python?

...ion without separate methods for every single type – Allen May 13 '15 at 4:33 29 It could be done...
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How can I add or update a query string parameter?

... @JarónBarends - Tweak value check to check against undefined and null to allow setting 0 values Third Update There was a bug where removing a querystring variable directly before a hashtag would lose the hashtag symbol which has been fixed Fourth Update Thanks @rooby for pointing out a regex o...