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Multiple aggregations of the same column using pandas GroupBy.agg()
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You can simply pass the functions as a list:
In [20]: df.groupby("dummy").agg({"returns": [np.mean, np.sum]})
Out[20]:
mean sum
dummy
1 0.036901 0.369012
or as a dictionary:
In [21]: df.groupby('dummy').agg({'returns':
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Convert columns to string in Pandas
...taFrame([['A', 2], ['A', 4], ['B', 6]])
In [12]: df.to_json()
Out[12]: '{"0":{"0":"A","1":"A","2":"B"},"1":{"0":2,"1":4,"2":6}}'
In [13]: df[0].to_json()
Out[13]: '{"0":"A","1":"A","2":"B"}'
Note: you can pass in a buffer/file to save this to, along with some other options...
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Fast stable sorting algorithm implementation in javascript
I'm looking to sort an array of about 200-300 objects, sorting on a specific key and a given order (asc/desc). The order of results must be consistent and stable.
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Remove rows with all or some NAs (missing values) in data.frame
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1080
Also check complete.cases :
> final[complete.cases(final), ]
gene hsap mmul m...
Filter rows which contain a certain string
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mpg cyl disp hp drat wt qsec vs am gear carb type
1 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4 Mazda RX4
2 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4 Mazda RX4 Wag
3 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1 Toyota Corolla
4 21.5 4 120.1 97 3....
pyplot scatter plot marker size
...xamples and the output they produce.
# doubling the width of markers
x = [0,2,4,6,8,10]
y = [0]*len(x)
s = [20*4**n for n in range(len(x))]
plt.scatter(x,y,s=s)
plt.show()
gives
Notice how the size increases very quickly. If instead we have
# doubling the area of markers
x = [0,2,4,6,8,10]
y ...
Conditional Replace Pandas
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.ix indexer works okay for pandas version prior to 0.20.0, but since pandas 0.20.0, the .ix indexer is deprecated, so you should avoid using it. Instead, you can use .loc or iloc indexers. You can solve this problem by:
mask = df.my_channel > 20000
column_name = 'my_chann...
Is there a Boolean data type in Microsoft SQL Server like there is in MySQL? [duplicate]
...e BIT datatype to represent boolean data. A BIT field's value is either 1, 0, or null.
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What's the idiomatic syntax for prepending to a short python list?
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The s.insert(0, x) form is the most common.
Whenever you see it though, it may be time to consider using a collections.deque instead of a list.
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Detect if Visual C++ Redistributable for Visual Studio 2012 is installed
How to detect if Visual C++ Redistributable for Visual Studio 2012 is installed?
20 Answers
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