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map function for objects (instead of arrays)
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38 Answers
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How to round to 2 decimals with Python?
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answered Dec 8 '13 at 18:20
roliszrolisz
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Pandas: create two new columns in a dataframe with values calculated from a pre-existing column
... from pandas import *
In [2]: def calculate(x):
...: return x*2, x*3
...:
In [3]: df = DataFrame({'a': [1,2,3], 'b': [2,3,4]})
In [4]: df
Out[4]:
a b
0 1 2
1 2 3
2 3 4
In [5]: df["A1"], df["A2"] = zip(*df["a"].map(calculate))
In [6]: df
Out[6]:
a b A1 A2
0 1 2 2...
How to group dataframe rows into list in pandas groupby?
..., 'b':[1,2,5,5,4,6]})
df
Out[1]:
a b
0 A 1
1 A 2
2 B 5
3 B 5
4 B 4
5 C 6
In [2]: df.groupby('a')['b'].apply(list)
Out[2]:
a
A [1, 2]
B [5, 5, 4]
C [6]
Name: b, dtype: object
In [3]: df1 = df.groupby('a')['b'].apply(list).reset_index(name='new')
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Concatenate two slices in Go
I'm trying to combine the slice [1, 2] and the slice [3, 4] . How can I do this in Go?
7 Answers
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Python - Create list with numbers between 2 values?
...t returns a list so all you need is:
>>> range(11, 17)
[11, 12, 13, 14, 15, 16]
In Python 3.x range is a iterator. So, you need to convert it to a list:
>>> list(range(11, 17))
[11, 12, 13, 14, 15, 16]
Note: The second number is exclusive. So, here it needs to be 16+1 = 17
E...
Pickle incompatibility of numpy arrays between Python 2 and 3
I am trying to load the MNIST dataset linked here in Python 3.2 using this program:
7 Answers
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Waiting until two async blocks are executed before starting another block
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305
Use dispatch groups: see here for an example, "Waiting on Groups of Queued Tasks" in the "Disp...
How to calculate moving average using NumPy?
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173
If you just want a straightforward non-weighted moving average, you can easily implement it with...