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Assignment inside lambda expression in Python
I have a list of objects and I want to remove all objects that are empty except for one, using filter and a lambda expression.
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How do I execute a string containing Python code in Python?
...;>> x
4
However, the first step should be to ask yourself if you really need to. Executing code should generally be the position of last resort: It's slow, ugly and dangerous if it can contain user-entered code. You should always look at alternatives first, such as higher order functions, ...
How to reset sequence in postgres and fill id column with new data?
... This might cause duplicate ids. To prevent this, you can first set all to very high values: UPDATE t SET idcolumn=1000000+ nextval('seq'); then run the above script.
– tahagh
Nov 28 '13 at 13:15
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Create list of single item repeated N times
I want to create a series of lists, all of varying lengths. Each list will contain the same element e , repeated n times (where n = length of the list).
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Remove last item from array
..., -1) will not. Pop is of course faster but may not be always suitable for all needs.
– adelriosantiago
Sep 23 '17 at 0:40
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MongoDB: How to update multiple documents with a single command?
...: 'field1', field2: 'field2'})
New in version 3.2
Params::
{}: select all records updated
Keyword argument multi not taken
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Mocking a class: Mock() or patch()?
...MyClass')
... def create_instance2(MyClass):
... MyClass.return_value = 'foo'
... return create_instance()
...
>>> i = create_instance2()
>>> i
'foo'
>>> def create_instance():
... print MyClass
... return MyClass()
...
>>> create_instance2()
<mock.Moc...
Why do you use typedef when declaring an enum in C++?
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In C, declaring your enum the first way allows you to use it like so:
TokenType my_type;
If you use the second style, you'll be forced to declare your variable like this:
enum TokenType my_type;
As mentioned by others, this doesn't make a difference in C++. M...
Creating a ZIP Archive in Memory Using System.IO.Compression
...pArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
}
using (var fileStream = new FileStream(@...
Why is it important to override GetHashCode when Equals method is overridden?
...ot match, they may never be considered equal (Equals will simply never be called).
The GetHashCode() method should reflect the Equals logic; the rules are:
if two things are equal (Equals(...) == true) then they must return the same value for GetHashCode()
if the GetHashCode() is equal, it is not...