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Java synchronized static methods: lock on object or class
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129
Since a static method has no associated object, will the synchronized keyword lock on the ...
Remove duplicated rows using dplyr
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139
Note: dplyr now contains the distinct function for this purpose.
Original answer below:
li...
How can I verify if one list is a subset of another?
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15 Answers
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How to find gaps in sequential numbering in mysql?
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11 Answers
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Code Golf: Lasers
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Perl, 166 160 characters
Perl, 251 248 246 222 214 208 203 201 193 190 180 176 173 170 166 --> 160 chars.
Solution had 166 strokes when this contest ended, but A. Rex has found a couple ways to shave off 6 more characters:
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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...
How to determine the number of days in a month in SQL Server?
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You can use the following with the first day of the specified month:
datediff(day, @date, dat...
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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google mock分享（全网最全最好的gmock文档，没有之一） - C/C++ - 清泛网 ...
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FooInterface的析构函数~FooInterface()必须是virtual的
在第13行，我们得把getArbitraryString定义为纯虚函数。其实getArbitraryString()也不一定得是纯虚函数，这点我们后面会提到.
现在我们用Google Mock来定义Mock类 FooMock.h
#ifndef MO...
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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