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Preferred Java way to ping an HTTP URL for availability
...ve to somehow close the connection?
No, you don't explicitly need. It's handled and pooled under the hoods.
I suppose this is a GET request. Is there a way to send HEAD instead?
You can cast the obtained URLConnection to HttpURLConnection and then use setRequestMethod() to set the request ...
Is there a standard function to check for null, undefined, or blank variables in JavaScript?
...re a universal JavaScript function that checks that a variable has a value and ensures that it's not undefined or null ? I've got this code, but I'm not sure if it covers all cases:
...
if/else in a list comprehension
...x in row]
In general,
[f(x) if condition else g(x) for x in sequence]
And, for list comprehensions with if conditions only,
[f(x) for x in sequence if condition]
Note that this actually uses a different language construct, a conditional expression, which itself is not part of the comprehensi...
项目管理实践【五】自动编译和发布网站【Using Visual Studio with Source ...
...和发布网站【Using Visual Studio with Source Control System to build and publish website automatically】在上一篇教程项目管理实践【三】每日构建【Daily Build Using CruiseControl NET and MSBuild】中，我们讲解了如何使用CCNET+MSBuild 在上一篇教程项目管理...
Why cast unused return values to void?
... it.
This is a way to ensure that where necessary error codes are always handled.
I think for C++ this is probably the only place that I prefer to use C-style casts too, since using the full static cast notation just feels like overkill here. Finally, if you're reviewing a coding standard or writ...
How can I check in a Bash script if my local Git repository has changes?
...u're doing will almost work: you should quote $CHANGED in case it's empty, and -z tests for empty, which means no changes. What you meant was:
if [ -n "$CHANGED" ]; then
VN="$VN-mod"
fi
A quote from Git's GIT-VERSION-GEN:
git update-index -q --refresh
test -z "$(git diff-index --name-only HE...
Remove a marker from a GoogleMap
In the new Google Maps API for Android, we can add a marker , but there is no way to (easily) remove one.
11 Answers
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Is there shorthand for returning a default value if None in Python? [duplicate]
In C#, I can say x ?? "" , which will give me x if x is not null, and the empty string if x is null. I've found it useful for working with databases.
...
Add default value of datetime field in SQL Server to a timestamp
...hey didn't put a timestamp in the table. I want it to enter the exact date and time that the record was entered.
12 Answers...
Setting different color for each series in scatter plot on matplotlib
...
I don't know what you mean by 'manually'. You can choose a colourmap and make a colour array easily enough:
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cm as cm
x = np.arange(10)
ys = [i+x+(i*x)**2 for i in range(10)]
colors = cm.rainbow(np.linspace(0, 1, len(ys)))
f...