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List of lists changes reflected across sublists unexpectedly
...s visible via all three references to it:
x = [1] * 4
l = [x] * 3
print(f"id(x): {id(x)}")
# id(x): 140560897920048
print(
f"id(l[0]): {id(l[0])}\n"
f"id(l[1]): {id(l[1])}\n"
f"id(l[2]): {id(l[2])}"
)
# id(l[0]): 140560897920048
# id(l[1]): 140560897920048
# id(l[2]): 140560897920048
x...
Use LINQ to get items in one List, that are not in another List
...sion:
var result = peopleList2.Where(p => !peopleList1.Any(p2 => p2.ID == p.ID));
An alternate way of expressing this via LINQ, which some developers find more readable:
var result = peopleList2.Where(p => peopleList1.All(p2 => p2.ID != p.ID));
Warning: As noted in the comments,...
Finding the id of a parent div using Jquery
...arent of the button.
The easiest of the two is probably the closest.
var id = $("button").closest("div").prop("id");
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Get the latest record from mongodb collection
...oDB are B-Trees. Searching a B-Tree is a O(logN) operation, so even find({_id:...}) will not provide constant time, O(1) responses.
That stated, you can also sort by the _id if you are using ObjectId for you IDs. See here for details. Of course, even that is only good to the last second.
You may t...
MySQL Error 1093 - Can't specify target table for update in FROM clause
...n case certain operations are carried out, merging cannot happen. E.g. provide the derived dummy table with a LIMIT (to inifity) and the error will never occur. That's pretty hackish though and there is still the risk that future versions of MySQL will support merging queries with LIMIT after all.
...
Foreign Key to multiple tables
...on your needs.
You could simply create two columns in Ticket, OwnedByUserId and OwnedByGroupId, and have nullable Foreign Keys to each table.
You could create M:M reference tables enabling both ticket:user and ticket:group relationships. Perhaps in future you will want to allow a single ticket to ...
Rails 3: Get Random Record
... on an indexed column (PostgreSQL syntax):
select *
from my_table
where id >= trunc(
random() * (select max(id) from my_table) + 1
)
order by id
limit 1;
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Switching the order of block elements with CSS [duplicate]
...ly need to support a single modern browser: Mobile Safari.
See: http://jsfiddle.net/thirtydot/hLUHL/
You can remove the -moz- prefixed properties if you like, I just left them in for future readers.
#blockContainer {
display: -webkit-box;
display: -moz-box;
disp...
What is the difference between shallow copy, deepcopy and normal assignment operation?
... 6]
c = [a, b]
Using normal assignment operatings to copy:
d = c
print id(c) == id(d) # True - d is the same object as c
print id(c[0]) == id(d[0]) # True - d[0] is the same object as c[0]
Using a shallow copy:
d = copy.copy(c)
print id(c) == id(d) # False - d is now a n...
PostgreSQL delete with inner join
...
DELETE
FROM m_productprice B
USING m_product C
WHERE B.m_product_id = C.m_product_id AND
C.upc = '7094' AND
B.m_pricelist_version_id='1000020';
or
DELETE
FROM m_productprice
WHERE m_pricelist_version_id='1000020' AND
m_product_id IN (SELECT m_product...