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Iterate through a HashMap [duplicate]
...t value : map.values()) {
// ...
}
Finally, if you want both the key and value, use entrySet():
for (Map.Entry<String, Object> entry : map.entrySet()) {
String key = entry.getKey();
Object value = entry.getValue();
// ...
}
One caveat: if you want to remove items mid-itera...
Storing DateTime (UTC) vs. storing DateTimeOffset
...ing from/to the database does DateTime conversion (from UTC to local time, and from local time to UTC), so I can use DateTime.Now (derivations and comparisions) throughout the system without worrying about time zones.
...
When should I use the HashSet type?
I am exploring the HashSet<T> type, but I don't understand where it stands in collections.
11 Answers
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When I catch an exception, how do I get the type, file, and line number?
..._info() into local variables, since if you get an exception in the except handler, the local vars could get kept in a circular reference and not GC'd. Best practice is to always just use slices off of sys.exc_info() instead. Or use other modules like traceback, as other posters have suggested.
...
Random string generation with upper case letters and digits
...
Answer in one line:
''.join(random.choice(string.ascii_uppercase + string.digits) for _ in range(N))
or even shorter starting with Python 3.6 using random.choices():
''.join(random.choices(string.ascii_uppercase + string.digits, k=N))
A cryptographi...
List files by last edited date
...
You can use:
ls -Rt
where -R means recursive (include subdirectories) and -t means "sort by last modification date".
To see a list of files sorted by date modified, use:
ls -l -Rt
An alias can also be created to achieve this:
alias lt='ls -lht'
lt
Where -h gives a more readable output....
CSS Display an Image Resized and Cropped
I want to show an image from an URL with a certain width and height even if it has a different size ratio.
So I want to resize (maintaining the ratio) and then cut the image to the size I want.
...
Difference between socket and websocket?
...lications that require a permanent connection to its server. On the other hand, plain sockets are more powerful and generic. They run over TCP/IP but they are not restricted to browsers or HTTP protocol. They could be used to implement any kind of communication.
No. There is no reason.
...
Declaring Multiple Variables in JavaScript
...ion is a single statement on a single line, so you can easily add, remove, and reorder the declarations.
With the second way, it is annoying to remove the first or last declaration because they start from the var keyword and finish with the semicolon respectively. Every time you add a new declaratio...
Getting A File's Mime Type In Java
... Be aware that Files.probeContentType(Path) is buggy on several OSes and a lot of bug reports have been filed. I have had a problem with software working on ubuntu but failing on windows. It seemed that on windows Files.probeContentType(Path) always returned null. It was not my system so I did...