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remove None value from a list without removing the 0 value
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10 Answers
10
Active
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How to form tuple column from two columns in Pandas
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208
Get comfortable with zip. It comes in handy when dealing with column data.
df['new_col'] = li...
All falsey values in JavaScript
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Falsey values in JavaScript
false
Zero of Number type: 0 and also -0, 0.0, and hex form 0x0 (thanks RBT)
Zero of BigInt type: 0n and -0n (new in 2020, thanks GetMeARemoteJob)
"", '' and `` - strings of length 0
null
undefined
NaN
document.all (in HTML browsers only)
This is a ...
Javascript calculate the day of the year (1 - 366)
... edit:
var now = new Date();
var start = new Date(now.getFullYear(), 0, 0);
var diff = now - start;
var oneDay = 1000 * 60 * 60 * 24;
var day = Math.floor(diff / oneDay);
console.log('Day of year: ' + day);
Edit: The code above will fail when now is a date in between march 26th and ...
How to initialize a two-dimensional array in Python?
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for i in range (0, 10): \
new = [] \ can be replaced } this too
for j in range (0, 10): } with a list /
new.append(foo) / comprehension /
twod...
How do I print a double value without scientific notation using Java?
...8;
System.out.printf("dexp: %f\n", dexp);
This will print dexp: 12345678.000000. If you don't want the fractional part, use
System.out.printf("dexp: %.0f\n", dexp);
This uses the format specifier language explained in the documentation.
The default toString() format used in your original code ...
How to debug Lock wait timeout exceeded on MySQL?
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Type: InnoDB
Name:
Status:
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110514 19:44:14 INNODB MONITOR OUTPUT
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Per second averages calculated from the last 4 seconds
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SEMAPHORES
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OS WAIT ARRAY INFO: reservation count 9014315, signal count 780...
How do you rotate a two dimensional array?
...ay you have a 4x4 two dimensional array, write a function that rotates it 90 degrees. Raymond links to a solution in pseudo code, but I'd like to see some real world stuff.
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Converting RGB to grayscale/intensity
...ic weights to channels R, G, and B ought to be applied. These weights are: 0.2989, 0.5870, 0.1140.
8 Answers
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How to find the kth smallest element in the union of two sorted arrays?
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50
You've got it, just keep going! And be careful with the indexes...
To simplify a bit I'll assum...