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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
....drop argument that does just what you asked for:
df = data.frame(a=rep(1:3,4), b=rep(1:2,6))
df$b = factor(df$b, levels=1:3)
df %>%
group_by(b, .drop=FALSE) %>%
summarise(count_a=length(a))
#> # A tibble: 3 x 2
#> b count_a
#> <fct> <int>
#> 1 1 ...
Is generator.next() visible in Python 3?
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3 Answers
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How to get the last N rows of a pandas DataFrame?
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PHP: merge two arrays while keeping keys instead of reindexing?
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You can simply 'add' the arrays:
>> $a = array(1, 2, 3);
array (
0 => 1,
1 => 2,
2 => 3,
)
>> $b = array("a" => 1, "b" => 2, "c" => 3)
array (
'a' => 1,
'b' => 2,
'c' => 3,
)
>> $a + $b
array (
0 => 1,
1 => 2,
2 =&g...
what is the function of webpages:Enabled in MVC 3 web.config
I just started a new MVC 3 project. Can anyone tell me what
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3
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Getting list of lists into pandas DataFrame
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Android: TextView automatically truncate and replace last 3 char of String
...oid:inputType="text" . What I need now is something that replaces the last 3 characters of my String with " ... ". Since I'm not using a monospace font this will always be different depending on the letters used in my String . So I'm wondering what's the best way to get the last 3 characters of a...
Accessing last x characters of a string in Bash
I found out that with ${string:0:3} one can access the first 3 characters of a string. Is there a equivalently easy method to access the last three characters?
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