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How do you use “
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function(x) x ^ exponent
}
square <- power(2)
square(2) # -> [1] 4
square(4) # -> [1] 16
cube <- power(3)
cube(2) # -> [1] 8
cube(4) # -> [1] 64
The ability to manage variables at two levels also makes it possible to maintain the state across function invocations by allowing...
How can I get the active screen dimensions?
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144
Screen.FromControl, Screen.FromPoint and Screen.FromRectangle should help you with this. For ex...
What's the best way of implementing a thread-safe Dictionary?
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43
As Peter said, you can encapsulate all of the thread safety inside the class. You will need to...
Sorting a Python list by two fields
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edited Sep 4 '15 at 8:54
BrechtDeMan
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How to replace NaN values by Zeroes in a column of a Pandas Dataframe?
...le:
In [7]: df
Out[7]:
0 1
0 NaN NaN
1 -0.494375 0.570994
2 NaN NaN
3 1.876360 -0.229738
4 NaN NaN
In [8]: df.fillna(0)
Out[8]:
0 1
0 0.000000 0.000000
1 -0.494375 0.570994
2 0.000000 0.000000
3 1.876360 -0.229738
4...
Primary key or Unique index?
...1 (foo, bar) VALUES (3, 1); -- OK
INSERT INTO table1 (foo, bar) VALUES (1, 4); -- Fails!
Duplicate entry '1' for key 'ux_table1_foo'
The last insert fails because it violates the unique index on column foo when it tries to insert the value 1 into this column for a second time.
In MySQL a unique ...
Best way to simulate “group by” from bash?
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14 Answers
14
Active
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What is the size limit of a post request?
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edited Dec 4 '16 at 23:44
Wolverine
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answered Ma...
How to fix homebrew permissions?
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edited Aug 14 '15 at 17:20
xji
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ans...
Simple way to repeat a String in java
...l Bourque
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answered Mar 2 '18 at 8:31
NicolaiNicolai
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