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Why is iterating through a large Django QuerySet consuming massive amounts of memory?
...rst time you iterate over it. For example, this will print the headline of all entries in the database:
for e in Entry.objects.all():
print e.headline
So your ten million rows are retrieved, all at once, when you first enter that loop and get the iterating form of the queryset. The wait ...
django unit tests without a db
... doesn't require the db to set up. And while it is fast to setup a db, I really don't need it in some situations.
11 Answer...
Converting string from snake_case to CamelCase in Ruby
...equire "active_support/core_ext/string" is suffice, providing Rails is installed already.
– Masa Sakano
Jun 23 '18 at 2:03
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Best practices for in-app database migration for Sqlite
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I maintain an application that periodically needs to update a sqlite database and migrate old databases to the new schema and here's what I do:
For tracking the database version, I use the built in user-version variable that sqlite provides (sqlite does nothing w...
How can I easily view the contents of a datatable or dataview in the immediate window
... of this solution: You don't need Visual Studio!
Here my example output:
SELECT PackKurz, PackName, PackGewicht FROM verpackungen
PackKurz | PackName | PackGewicht |
---------------------|----------------------|----------------------|-
BB205 | BigB...
Adding IN clause List to a JPA Query
...need (...):
@NamedQuery(name = "EventLog.viewDatesInclude",
query = "SELECT el FROM EventLog el WHERE el.timeMark >= :dateFrom AND "
+ "el.timeMark <= :dateTo AND "
+ "el.name IN :inclList")
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Sublime Text 2 and 3: open the same file multiple times
... the file in.
Type Ctrl-p (Mac: ⌘-p) to get the list of files available.
Select the one you're after and it will be loaded into the current pane
(Even if it's already open in another pane.)
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Python: split a list based on a condition?
What's the best way, both aesthetically and from a performance perspective, to split a list of items into multiple lists based on a conditional? The equivalent of:
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Web-scraping JavaScript page with Python
...a web driver fast enough and easy to get the work done.
Once you have installed Phantom JS, make sure the phantomjs binary is available in the current path:
phantomjs --version
# result:
2.1.1
Example
To give an example, I created a sample page with following HTML code. (link):
<!DOCTYPE ht...
Can't delete virtual device from Eclipse, android
...e inside [Your Device].avd folder
From Android Studio
Open AVD Manager
Select virtual device that you want to delete
Click down arrow at the end and select [Show on Disk] it will open directory
Find *.lock files and delete inside [Your Device].avd folder
After these steps it will allow you to ...