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Pandas aggregate count distinct
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How about either of:
>>> df
date duration user_id
0 2013-04-01 30 0001
1 2013-04-01 15 0001
2 2013-04-01 20 0002
3 2013-04-02 15 0002
4 2013-04-02 30 0002
>>> df.groupby("date").agg({"duration": np.sum, "use...
Is there a pattern for initializing objects created via a DI container
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{
get { return this.runTimeParam; }
}
}
Notice how this allows us to protect the class' invariants by use of the readonly keyword. No smelly Initialize methods are necessary.
An IMyIntfFactory implementation may be as simple as this:
public class MyIntfFactory : IMyIntfFactory
{...
(Mac) -bash: __git_ps1: command not found
...r - in git's development history this is after a commit that split out the __git_ps1 function from the completion functionality into a new file (git-prompt.sh). The commit that introduced this change, which explains the rationale, is af31a456.
I would still suggest that you just source the version...
How do I declare a 2d array in C++ using new?
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A dynamic 2D array is basically an array of pointers to arrays. You can initialize it using a loop, like this:
int** a = new int*[rowCount];
for(int i = 0; i < rowCount; ++i)
a[i] = new int[colCount];
The above, for colCount= 5 and rowCount =...
Why doesn't Haskell's Prelude.read return a Maybe?
...ersions floating around many codebases).
See also this discussion.
Personally, I use the version from the safe package.
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if else in a list comprehension [duplicate]
...with a specific condition (name in this example) var_list = [v for v in tf.all_variables() if v.name == 'C:0']
– Charlie Parker
Jul 25 '16 at 16:50
13
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Does R have an assert statement as in python?
...ndition that will throw an error in your program. Here's an example:
Less_Than_8 = function(x) return(x < 8)
for (i in 1:10)
{
print(i)
stopifnot(Less_Than_8(i))
}
This will print the numbers 1 through 8, then print a message that says
Error: Less_Than_8(i) is not TRUE
It would be ni...
Insert auto increment primary key to existing table
...ering if it's possible to insert data into the primary key column automatically (I already have 500 rows in DB and want to give them id but I don't want to do it manually). Any thoughts? Thanks a lot.
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Integrating the ZXing library directly into my Android application
...de so it hopefully can help others with the same problem as I had ;)
Install Apache Ant - (See this YouTube video for config help)
Download the ZXing source from ZXing homepage and extract it
With the use of Windows Commandline (Run->CMD) navigate to the root directory of the downloaded zxing s...
Referring to the null object in Python
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SyntaxError: cannot assign to keyword
It's therefore safe to assume that all None references are the same. There isn't any "custom" None.
To test for None use the is operator
When writing code you might be tempted to test for Noneness like this:
if value==None:
pass
Or to test for falsehood l...