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How do I get the number of elements in a list?
...turns 3.
Explanation
Everything in Python is an object, including lists. All objects have a header of some sort in the C implementation.
Lists and other similar builtin objects with a "size" in Python, in particular, have an attribute called ob_size, where the number of elements in the object is...
Can modules have properties the same way that objects can?
...s? When I put this code in one file x.py and import it from another, then calling x.y results in AttributeError: 'NoneType' object has no attribute 'c', since _M somehow has value None...
– Stephan202
May 19 '09 at 1:35
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How to make my custom type to work with “range-based for loops”?
...hanges, and compilers that do not.
The objects returned do not have to actually be iterators. The for(:) loop, unlike most parts of the C++ standard, is specified to expand to something equivalent to:
for( range_declaration : range_expression )
becomes:
{
auto && __range = range_expressi...
How to get the currently logged in user's user id in Django?
...rs = [{user.id: user.get_name()} for user in logged_in_users]
# Query all logged in staff users based on id list
all_staff_users = CustomUser.objects.filter(is_resident=False, is_active=True, is_superuser=False)
logged_out_users = list()
# for some reason exclude() would not work co...
MongoDB/NoSQL: Keeping Document Change History
... changes to one or more specific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can write all changes from all source tables to a single table (more of...
What is the difference between char array and char pointer in C?
...char* and char[] are different types, but it's not immediately apparent in all cases. This is because arrays decay into pointers, meaning that if an expression of type char[] is provided where one of type char* is expected, the compiler automatically converts the array into a pointer to its first el...
Any reason not to use '+' to concatenate two strings?
... Tuple would be faster - the code was just an example :) Usually long multiple string inputs are dynamic.
– Mikko Ohtamaa
Apr 6 '12 at 12:52
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What tools are there for functional programming in C?
...ing in C ( not C++). Obviously, C is a procedural language and doesn't really support functional programming natively.
13...
Mathematical functions in Swift
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UIKit, Cocoa, Foundation, all valid choices.
– erdekhayser
Nov 27 '14 at 20:26
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How to convert an enum type variable to a string?
...
There really is no beautiful way of doing this. Just set up an array of strings indexed by the enum.
If you do a lot of output, you can define an operator<< that takes an enum parameter and does the lookup for you.
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