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How to take the first N items from a generator or list in Python? [duplicate]
...imple syntax: array[start:stop:step]
You can omit any parameter. These are all valid: array[start:], array[:stop], array[::step]
Slicing a generator
import itertools
top5 = itertools.islice(my_list, 5) # grab the first five elements
You can't slice a generator directly in Python. itertools.i...
Filter element based on .data() key/value
...sentially equivalent. Using .find() seems like it may be slower due to the extra function call (although I'm not positive about this). Please correct me if I'm wrong about any of this (I really wish this method worked).
– Bryan Downing
Feb 25 '13 at 22:24
...
Maximum Java heap size of a 32-bit JVM on a 64-bit OS
...sk the Java Runtime:
public class MaxMemory {
public static void main(String[] args) {
Runtime rt = Runtime.getRuntime();
long totalMem = rt.totalMemory();
long maxMem = rt.maxMemory();
long freeMem = rt.freeMemory();
double megs = 1048576.0;
Sys...
Implement touch using Python?
...
On Python2.7: pip install pathlib
– Andre Miras
Oct 24 '17 at 17:54
8
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Heroku Postgres - terminate hung query (idle in transaction)
...
You can install the heroku-pg-extras add-on and run the following command to get the PID:
heroku pg:locks --app <your-app>
Then just do:
heroku pg:kill <pid> --app <your-app>
NOTE: --force option can be used to issue pg_terminate_...
How do I update the notification text for a foreground service in Android?
...tivityNotification(""));
}
private Notification getMyActivityNotification(String text){
// The PendingIntent to launch our activity if the user selects
// this notification
CharSequence title = getText(R.string.title_activity);
PendingIntent contentIntent = PendingIntent.getActivity...
Loop backwards using indices in Python?
... This is better than the accepted answer since it doesn't actually allocate all the numbers in memory (in Python 3 the accepted answer wouldn't either), plus it's more obvious what is happening.
– Blixt
Mar 23 '12 at 13:52
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Creating temporary files in bash
...
Ignore they typo (extra space). mktemp -dt "$(basename $0).XXXXXXXXXX" is the correct way.
– i4niac
May 28 '14 at 2:06
3
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Python: print a generator expression?
... [] brackets around it. So yeah, you can do
>>> list((x for x in string.letters if x in (y for y in "BigMan on campus")))
But you can just as well do
>>> [x for x in string.letters if x in (y for y in "BigMan on campus")]
Yes, that will turn the generator expression into a li...
Why is it important to override GetHashCode when Equals method is overridden?
...
How about:
public override int GetHashCode()
{
return string.Format("{0}_{1}_{2}", prop1, prop2, prop3).GetHashCode();
}
Assuming performance is not an issue :)
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