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Pandas dataframe get first row of each group
...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 first
6 7 fourth
To get n first records, you can use head():
>>> df.groupby('id').head(2).reset_index(drop=True)
id value
0 ...
Double vs. BigDecimal?
...s a certain precision. Working with doubles of various magnitudes (say d1=1000.0 and d2=0.001) could result in the 0.001 being dropped alltogether when summing as the difference in magnitude is so large. With BigDecimal this would not happen.
The disadvantage of BigDecimal is that it's slower, and ...
Equivalent of String.format in jQuery
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20 Answers
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How do you push a Git tag to a branch using a refspec?
I want to force push, for example, my tag 1.0.0 to my remote master branch.
4 Answers
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Why does the indexing start with zero in 'C'?
...f the array is exactly contained in the memory location that array refers (0 elements away), so it should be denoted as array[0].
For more info:
http://developeronline.blogspot.com/2008/04/why-array-index-should-start-from-0.html
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How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops
...ns:
- Range.
E.g. a-z matches an lower case letters from a to z
E.g. 0-5 matches any number from 0 to 5
[] Match exactly one of the objects inside these brackets.
E.g. [a] matches the letter a
E.g. [abc] matches a single letter which can be a, b or c
E.g. [a-z] matches any single lower cas...
Initialising an array of fixed size in python [duplicate]
...sked.
– samplebias
Aug 25 '14 at 21:08
3
This meets the requirements of the question because you ...
How to extract numbers from a string and get an array of ints?
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answered Mar 2 '10 at 22:39
Sean OwenSean Owen
62.6k1919 gold badges130130 silver badges163163 bronze badges
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Bitwise operation and usage
...bit at a time.
AND is 1 only if both of its inputs are 1, otherwise it's 0.
OR is 1 if one or both of its inputs are 1, otherwise it's 0.
XOR is 1 only if exactly one of its inputs are 1, otherwise it's 0.
NOT is 1 only if its input is 0, otherwise it's 0.
These can often be best shown as truth ...
How to count total lines changed by a specific author in a Git repository?
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320
The output of the following command should be reasonably easy to send to script to add up the to...