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Pandas dataframe get first row of each group
...;> df.groupby('id').first()
value
id
1 first
2 first
3 first
4 second
5 first
6 first
7 fourth
If you need id as column:
>>> df.groupby('id').first().reset_index()
id value
0 1 first
1 2 first
2 3 first
3 4 second
4 5 first
5 6...
Read user input inside a loop
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answered Jul 30 '11 at 13:42
dankdank
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How to cast int to enum in C++?
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answered Jul 12 '12 at 13:33
AndrewAndrew
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How to initialize all members of an array to the same value in Swift?
...ue like this:
With old Swift version:
var threeDoubles = [Double](count: 3, repeatedValue: 0.0)
Since Swift 3.0:
var threeDoubles = [Double](repeating: 0.0, count: 3)
which would give:
[0.0, 0.0, 0.0]
share
...
How to add a new row to an empty numpy array
...
237
The way to "start" the array that you want is:
arr = np.empty((0,3), int)
Which is an empty ...
Pass a variable into a partial, rails 3?
...
237
Try this:
<% @posts.each do |post| %>
<%= render 'middle', :post => post %>
&...
Should I use encoding declaration in Python 3?
Python 3 uses UTF-8 encoding for source-code files by default. Should I still use the encoding declaration at the beginning of every source file? Like # -*- coding: utf-8 -*-
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Clojure: cons (seq) vs. conj (list)
...ments to insert into a collection, while cons takes just one:
(conj '(1 2 3) 4 5 6)
; => (6 5 4 1 2 3)
(cons 4 5 6 '(1 2 3))
; => IllegalArgumentException due to wrong arity
Another difference is in the class of the return value:
(class (conj '(1 2 3) 4))
; => clojure.lang.PersistentLi...
Python pandas Filtering out nan from a data selection of a column of strings
...NaN:
In [87]:
nms
Out[87]:
movie name rating
0 thg John 3
1 thg NaN 4
3 mol Graham NaN
4 lob NaN NaN
5 lob NaN NaN
[5 rows x 3 columns]
In [89]:
nms = nms.dropna(thresh=2)
In [90]:
nms[nms.name.notnull()]
Out[90]:
movie name rating
0...