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How can you profile a Python script?
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Python includes a profiler called cProfile. It not only gives the total running time, but also times each function separately, and tells you how many times each function was called, making it easy to determine where you should make optimizations.
You c...
What is a memory fence?
...ead/writes occur in the order you expect. For example a 'full fence' means all read/writes before the fence are comitted before those after the fence.
Note memory fences are a hardware concept. In higher level languages we are used to dealing with mutexes and semaphores - these may well be implemen...
Count how many records are in a CSV Python?
...aranteed to be a fixed size, so the only way to count them is to read them all.
– Martijn Pieters♦
Apr 19 '13 at 15:55
1
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How to use clock() in C++
How do I call clock() in C++ ?
7 Answers
7
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Change MySQL default character set to UTF-8 in my.cnf?
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The above my.cnf settings worked for me as well. Additionally, I had to make sure the table was set properly, such as ALTER TABLE Table CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;
– Chris Livdahl
May 26 '11 at 19:26
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Facebook API - How do I get a Facebook user's profile image through the Facebook API (without requir
...m/users_unique_url ). How can I accomplish this? Is there a Faceboook API call that fetches a user's profile image URL without the user needing to Allow the application?
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Outputting data from unit test in python
... %r", self.that )
# etc.
self.assertEquals( 3.14, pi )
if __name__ == "__main__":
logging.basicConfig( stream=sys.stderr )
logging.getLogger( "SomeTest.testSomething" ).setLevel( logging.DEBUG )
unittest.main()
That allows us to turn on debugging for specific tests whi...
Adding :default => true to boolean in existing Rails column
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change_column is a method of ActiveRecord::Migration, so you can't call it like that in the console.
If you want to add a default value for this column, create a new migration:
rails g migration add_default_value_to_show_attribute
Then in the migration created:
# That's the more generic way t...
Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...an work around it from within psql by executing the DDL statement conditionally:
SELECT 'CREATE DATABASE mydb'
WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'mydb')\gexec
The manual:
\gexec
Sends the current query buffer to the server, then treats each column of each row of the query's...
How to deep copy a list?
... don't make a deep copy using list() (Both list(...) and testList[:] are shallow copies).
You use copy.deepcopy(...) for deep copying a list.
deepcopy(x, memo=None, _nil=[])
Deep copy operation on arbitrary Python objects.
See the following snippet -
>>> a = [[1, 2, 3], [4, 5, 6]]...