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Get lengths of a list in a jinja2 template
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You could use none build-in function to test for None. Check more here: https://jinja.palletsprojects.com/en/2.10.x/templates/#none. Example is on this thread: https://stackoverflow.com/questions/19614027/jinja2-template-variable-if-none-object-set-a-default-value
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To find whether a column exists in data frame or not
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You could also use if(!is.null(abcframe$d)) to test whether d exists in abcframe.
dat <- data.frame(a = 1:2, b = 2:3, c = 4:5)
if (!is.null(dat$d)) {
print("d exists")
} else {
print("d does not exist")
}
if (!is.null(dat$a)) {
print("a exists")
} else {
prin...
How to check that a string is a palindrome using regular expressions?
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In an oral test zou shoulsd go with "formalz it is impossible", but you should point out that some regex engines allow it.
– Oliver A.
Oct 9 '15 at 21:30
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How can I make robocopy silent in the command line except for progress?
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I test > log:nul under win8.1 x64, there is a empty log file. > nul works as expected.
– Ivan Yan
Apr 4 '15 at 14:03
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Best way to convert an ArrayList to a string
...or.
You can implement it by yourself, of course, but their code is fully tested and is probably the best possible implementation.
I am a big fan of the Apache Commons library and I also think it's a great addition to the Java Standard Library.
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How to apply a function to two columns of Pandas dataframe
...s to be taken around datatypes.
In your example, you would (as I did when testing the answer) naively call
df['col_3'] = df.col_1.combine(df.col_2, func=get_sublist)
However, this throws the error:
ValueError: setting an array element with a sequence.
My best guess is that it seems to expec...
How to create a JavaScript callback for knowing when an image is loaded?
... setTimeout(function(){
logo.src = 'https://edmullen.net/test/rc.jpg';
}, 5000);
};
<html>
<head>
<title>Image onload()</title>
</head>
<body>
<img src="#" alt="This image is going to load" i...
Ways to implement data versioning in MongoDB
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I've done some testing and indeed the space reservation works pretty well. I wasn't able to catch the performance loss when the records were reallocated to the end of the data file.
– Piotr Czapla
Nov ...
Formatting Phone Numbers in PHP
...'/\D/', '', $out)) return false;
return $out;
}
And here's the script to test it:
$numbers = [
'3334444',
'2223334444',
'12223334444',
'12223334444x5555',
'333-4444',
'(222)333-4444',
'+1 222-333-4444',
'1-222-333-4444ext555',
'cell: (222) 333-4444',
'(222) 333-4444 (cell)',
];
foreach($numbers ...
Detect home button press in android
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check the accepted answer, it is possible. Not tested on many devices yet though.
– Dean Wild
Jan 16 '12 at 17:31
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