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Drop rows with all zeros in pandas data frame
I can use pandas dropna() functionality to remove rows with some or all columns set as NA 's. Is there an equivalent function for dropping rows with all columns having value 0?
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How do I efficiently iterate over each entry in a Java Map?
If I have an object implementing the Map interface in Java and I wish to iterate over every pair contained within it, what is the most efficient way of going through the map?
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All falsey values in JavaScript
...ing that they evaluate as false in expressions like if(value) , value ? and !value ?
4 Answers
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Swapping column values in MySQL
I have a MySQL table with coordinates, the column names are X and Y. Now I want to swap the column values in this table, so that X becomes Y and Y becomes X. The most apparent solution would be renaming the columns, but I don't want to make structure changes since I don't necessarily have permission...
Change Bootstrap input focus blue glow
..., 0.075), 0 0 8px rgba(255, 0, 0, 0.6);
}
Put it in your custom css file and load it after bootstrap.css. It will apply to all inputs including textarea, select etc...
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How to check if hex color is “too black”?
...e darkness of a color chosen by a color picker to see if it's "too black", and if so, set it to white. I thought I could use the first characters of the hex value to pull this off. It's working, but it's switching some legitimately "light" colors too.
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Should I return EXIT_SUCCESS or 0 from main()?
...IT_SUCCESS when it succeeds, just for the sake of symmetry.
On the other hand, if the program never signals failure, you can use either 0 or EXIT_SUCCESS. Both are guaranteed by the standard to signal successful completion. (It's barely possible that EXIT_SUCCESS could have a value other than 0, ...
What is the easiest way to remove the first character from a string?
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p asdf
# >> "12,23,987,43"
I'm always looking for the fastest and most readable way of doing things:
require 'benchmark'
N = 1_000_000
puts RUBY_VERSION
STR = "[12,23,987,43"
Benchmark.bm(7) do |b|
b.report('[0]') { N.times { "[12,23,987,43"[0] = '' } }
b.report('sub') { N.time...
Is there a simple way to remove multiple spaces in a string?
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This solution only handles single space characters. It wouldn't replace a tab or other whitespace characters handled by \s like in nsr81's solution.
– Taylor Leese
Oct 9 '09 at 22:21
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Compare double to zero using epsilon
Today, I was looking through some C++ code (written by somebody else) and found this section:
11 Answers
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