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What's the difference between dependencies, devDependencies and peerDependencies in npm package.json
...didn't understand those explanations. Can someone say in simpler words? Maybe with examples if it's hard to choose simple words?
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Which is the preferred way to concatenate a string in Python?
Since Python's string can't be changed, I was wondering how to concatenate a string more efficiently?
12 Answers
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Is there a ceiling equivalent of // operator in Python?
I found out about the // operator in Python which in Python 3 does division with floor.
7 Answers
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How do I remove duplicates from a C# array?
I have been working with a string[] array in C# that gets returned from a function call. I could possibly cast to a Generic collection, but I was wondering if there was a better way to do it, possibly by using a temp array.
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How to use sidebar with the keyboard in Sublime Text 2 and 3?
When using Sublime Text 2 we tend to open the side bar to navigate thru files/folders in our projects. For that we can use the hotkey ctrl+k ctrl+b (in windows).
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UPDATE multiple tables in MySQL using LEFT JOIN
I have two tables, and want to update fields in T1 for all rows in a LEFT JOIN.
5 Answers
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What is the difference between . (dot) and $ (dollar sign)?
What is the difference between the dot (.) and the dollar sign ($) ?
13 Answers
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From ND to 1D arrays
...(for an 1D iterator):
In [12]: a = np.array([[1,2,3], [4,5,6]])
In [13]: b = a.ravel()
In [14]: b
Out[14]: array([1, 2, 3, 4, 5, 6])
Note that ravel() returns a view of a when possible. So modifying b also modifies a. ravel() returns a view when the 1D elements are contiguous in memory, but wou...
Do I need to explicitly call the base virtual destructor?
...I am implementing the destructor again as virtual on the inheriting class, but do I need to call the base destructor?
7 Ans...
Pandas DataFrame Groupby two columns and get counts
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Followed by @Andy's answer, you can do following to solve your second question:
In [56]: df.groupby(['col5','col2']).size().reset_index().groupby('col2')[[0]].max()
Out[56]:
0
col2
A 3
B 2
C 1
D 3
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