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In Jinja2, how do you test if a variable is undefined?
...
From the Jinja2 template designer documentation:
{% if variable is defined %}
value of variable: {{ variable }}
{% else %}
variable is not defined
{% endif %}
share
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java.lang.IllegalArgumentException: View not attached to window manager
...Override
protected void onPostExecute(MyResult result) {
try {
if ((this.mDialog != null) && this.mDialog.isShowing()) {
this.mDialog.dismiss();
}
} catch (final IllegalArgumentException e) {
// Handle or log or ignore
} catch (final Exception ...
How to determine equality for two JavaScript objects?
A strict equality operator will tell you if two object types are equal. However, is there a way to tell if two objects are equal, much like the hash code value in Java?
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How is __eq__ handled in Python and in what order?
...ow how to compare themselves to B's, Python tries invoking B.__eq__ to see if it knows how to compare itself to an int.
If you amend your code to show what values are being compared:
class A(object):
def __eq__(self, other):
print("A __eq__ called: %r == %r ?" % (self, other))
...
Does VBA have Dictionary Structure?
...ictionary")
or
Dim dict As New Scripting.Dictionary
Example of use:
If Not dict.Exists(key) Then
dict.Add key, value
End If
Don't forget to set the dictionary to Nothing when you have finished using it.
Set dict = Nothing
...
How do C++ class members get initialized if I don't do it explicitly?
...emebers ptr , name , pname , rname , crname and age . What happens if I don't initialize them myself? Here is an example:
...
design a stack such that getMinimum( ) should be O(1)
.... Note that this doesn't change the complexity of the space required, e.g. if you've got a stack with O(n) space requirements, this will still be O(n) just with a different constant factor.
Non-constant-space solution
Keep a "duplicate" stack of "minimum of all values lower in the stack". When you...
Why is Python running my module when I import it, and how do I stop it?
...t declarations. Instead, they are real live statements which are executed. If they were not executed your module would be .. empty :-)
Anyway, the idiomatic approach is:
# stuff to run always here such as class/def
def main():
pass
if __name__ == "__main__":
# stuff only to run when not ca...
How do I get the first element from an IEnumerable in .net?
...
If you can use LINQ you can use:
var e = enumerable.First();
This will throw an exception though if enumerable is empty: in which case you can use:
var e = enumerable.FirstOrDefault();
FirstOrDefault() will return defau...
In C# check that filename is *possibly* valid (not that it exists) [duplicate]
...tch (System.IO.PathTooLongException) { }
catch (NotSupportedException) { }
if (ReferenceEquals(fi, null)) {
// file name is not valid
} else {
// file name is valid... May check for existence by calling fi.Exists.
}
For creating a FileInfo instance the file does not need to exist.
...