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LINQ Select Distinct with Anonymous Types
...lt;T> : IEqualityComparer<T>
{
private Func<T, T, bool> _equals;
private Func<T, int> _hashCode;
public DelegateComparer(Func<T, T, bool> equals, Func<T, int> hashCode)
{
_equals= equals;
_hashCode = hashCode;
}
public bool Equ...
Why does 'continue' behave like 'break' in a Foreach-Object?
..., it simulates the continue in a loop.
1..100 | ForEach-Object {
if ($_ % 7 -ne 0 ) { return }
Write-Host "$($_) is a multiple of 7"
}
There is a gotcha to be kept in mind when refactoring. Sometimes one wants to convert a foreach statement block into a pipeline with a ForEach-Object cmdl...
Reload django object from database
...
As of Django 1.8 refreshing objects is built in. Link to docs.
def test_update_result(self):
obj = MyModel.objects.create(val=1)
MyModel.objects.filter(pk=obj.pk).update(val=F('val') + 1)
# At this point obj.val is still 1, but the value in the database
# was updated to 2. The ob...
wkhtmltopdf: cannot connect to X server
...ble, so no need to make the wrapper script.
– jeffery_the_wind
Mar 13 '12 at 13:43
it worked for me.. in some situatio...
Creating a dynamic choice field
...passing the user to the form init
class waypointForm(forms.Form):
def __init__(self, user, *args, **kwargs):
super(waypointForm, self).__init__(*args, **kwargs)
self.fields['waypoints'] = forms.ChoiceField(
choices=[(o.id, str(o)) for o in Waypoint.objects.filter(use...
Is there a built-in function to print all the current properties and values of an object?
So what I'm looking for here is something like PHP's print_r function.
25 Answers
25...
Purpose of Python's __repr__
...
__repr__ should return a printable representation of the object, most likely one of the ways possible to create this object. See official documentation here. __repr__ is more for developers while __str__ is for end users.
A ...
Django set default form values
...
@Phlip: Don't override View.get_form to set initial data. Any CBV with a FormMixin (basically all CBVs that create or edit data) can either use a class-level initial variable (for unchanging defaults) or you can override FormMixin.get_initial() to return ...
'await' works, but calling task.Result hangs/deadlocks
... following four tests and the last one hangs when I run it. Why does this happen:
5 Answers
...
Sleep until a specific time/date
... correct number of seconds.
To do this in bash, do the following:
current_epoch=$(date +%s)
target_epoch=$(date -d '01/01/2010 12:00' +%s)
sleep_seconds=$(( $target_epoch - $current_epoch ))
sleep $sleep_seconds
To add precision down to nanoseconds (effectively more around milliseconds) use e....