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How to update SQLAlchemy row entry?
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137
user.no_of_logins += 1
session.commit()
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The maximum value for an int type in Go
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10 Answers
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How to determine the number of days in a month in SQL Server?
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116
You can use the following with the first day of the specified month:
datediff(day, @date, dat...
How can I verify if one list is a subset of another?
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15 Answers
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Remove duplicated rows using dplyr
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139
Note: dplyr now contains the distinct function for this purpose.
Original answer below:
li...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
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13 Answers
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Why is January month 0 in Java Calendar?
In java.util.Calendar , January is defined as month 0, not month 1. Is there any specific reason to that ?
16 Answers
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Convert columns to string in Pandas
...will convert keys to valid json (and therefore your keys to strings):
In [11]: df = pd.DataFrame([['A', 2], ['A', 4], ['B', 6]])
In [12]: df.to_json()
Out[12]: '{"0":{"0":"A","1":"A","2":"B"},"1":{"0":2,"1":4,"2":6}}'
In [13]: df[0].to_json()
Out[13]: '{"0":"A","1":"A","2":"B"}'
Note: you can p...
Is log(n!) = Θ(n·log(n))?
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Remember that
log(n!) = log(1) + log(2) + ... + log(n-1) + log(n)
You can get the upper bound by
log(1) + log(2) + ... + log(n) <= log(n) + log(n) + ... + log(n)
= n*log(n)
And you can get the lower bound by doin...