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Split delimited strings in a column and insert as new rows [duplicate]
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As of Dec 2014, this can be done using the unnest function from Hadley Wickham's tidyr package (see release notes http://blog.rstudio.org/2014/12/08/tidyr-0-2-0/)
> library(tidyr)
> library(dplyr)
> mydf
V1 V2
2 1 a,b,c
3 2 a,c
4 3 b,d
5 4 e,f
6 . .
&...
How do I retrieve the number of columns in a Pandas data frame?
... my guess is that it does not call a function but just reads the attribute from memory?
– mkln
Nov 30 '13 at 18:59
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Does Java have a complete enum for HTTP response codes?
... for all of the valid HTTP response codes. It should support conversion to/from the corresponding integer values.
11 Answer...
What is the difference between String and string in C#?
...ouble: System.Double
decimal: System.Decimal
char: System.Char
Apart from string and object, the aliases are all to value types. decimal is a value type, but not a primitive type in the CLR. The only primitive type which doesn't have an alias is System.IntPtr.
In the spec, the value type alia...
What are Flask Blueprints, exactly?
...version of its structure in the plaster of your application.
# An example
from flask import Blueprint
tree_mold = Blueprint("mold", __name__)
@tree_mold.route("/leaves")
def leaves():
return "This tree has leaves"
@tree_mold.route("/roots")
def roots():
return "And roots as well"
@tree_...
How to check if a file exists from inside a batch file [duplicate]
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Try something like the following example, quoted from the output of IF /? on Windows XP:
IF EXIST filename. (
del filename.
) ELSE (
echo filename. missing.
)
You can also check for a missing file with IF NOT EXIST.
The IF command is quite powerful. The output ...
Get Month name from month number
I used the following c# syntax to get month name from month no but i get August i want only Aug ..
8 Answers
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Find Oracle JDBC driver in Maven repository
...omputer repository with (note I pulled the groupId, artifactId and version from the POM):
mvn install:install-file -DgroupId=com.oracle -DartifactId=ojdbc14 \
-Dversion=10.2.0.3.0 -Dpackaging=jar -Dfile=ojdbc.jar -DgeneratePom=true
The last parameter for generating a POM will save you from p...
Checking if a variable is not nil and not zero in ruby
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From Ruby 2.3.0 onward, you can combine the safe navigation operator (&.) with Numeric#nonzero?. &. returns nil if the instance was nil and nonzero? - if the number was 0:
if discount&.nonzero?
# ...
end
Or p...
Why is Java's Iterator not an Iterable?
...instance in a collection. Iterable implies that one may obtain an iterator from an object to traverse over its elements - and there's no need to iterate over a single instance, which is what an iterator represents.
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