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Pandas: create two new columns in a dataframe with values calculated from a pre-existing column
I am working with the pandas library and I want to add two new columns to a dataframe df with n columns (n > 0).
These new columns result from the application of a function to one of the columns in the dataframe.
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How does zip(*[iter(s)]*n) work in Python?
... zip(*[iter(s)]*n) work? What would it look like if it was written with more verbose code?
6 Answers
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Regex lookahead for 'not followed by' in grep
I am attempting to grep for all instances of Ui\. not followed by Line or even just the letter L
5 Answers
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How do I ignore the initial load when watching model changes in AngularJS?
...eep graph in the $scope.fieldcontainer property. After I get a response from my REST API (via $resource), I add a watch to 'fieldcontainer'. I am using this watch to detect if the page/entity is "dirty". Right now I'm making the save button bounce but really I want to make the save button invisible ...
Finding Number of Cores in Java
How can I find the number of cores available to my application from within Java code?
4 Answers
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What is the right way to override a setter method in Ruby on Rails?
I am using Ruby on Rails 3.2.2 and I would like to know if the following is a "proper"/"correct"/"sure" way to override a setter method for a my class attribute.
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How can I obtain the element-wise logical NOT of a pandas Series?
... False
1 False
2 True
3 False
dtype: bool
Using Python2.7, NumPy 1.8.0, Pandas 0.13.1:
In [119]: s = pd.Series([True, True, False, True]*10000)
In [10]: %timeit np.invert(s)
10000 loops, best of 3: 91.8 µs per loop
In [11]: %timeit ~s
10000 loops, best of 3: 73.5 µs per loop
In ...
How to use > in an xargs command?
I want to find a bash command that will let me grep every file in a directory and write the output of that grep to a separate file. My guess would have been to do something like this
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Insert Unicode character into JavaScript
I need to insert an Omega (Ω) onto my html page. I am using its HTML escaped code to do that, so I can write Ω and get Ω. That's all fine and well when I put it into a HTML element; however, when I try to put it into my JS, e.g. var Omega = Ω , it parses that code as JS and th...
How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
I have a dataframe with ~300K rows and ~40 columns.
I want to find out if any rows contain null values - and put these 'null'-rows into a separate dataframe so that I could explore them easily.
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