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Upgrade python in a virtualenv
...tand that answer, you may try to create a new virtualenv on top of the old one. You just need to know which python is going to use your virtualenv (you will need to see your virtualenv version).
If your virtualenv is installed with the same python version of the old one and upgrading your virtuale...
Understanding typedefs for function pointers in C
...d returns a SignalHandler.
It takes a bit of getting used to, though. The one thing you can't do, though is write a signal handler function using the SignalHandler typedef in the function definition.
I'm still of the old-school that prefers to invoke a function pointer as:
(*functionpointer)(arg1, ...
How can I break up this long line in Python?
... is to join string literals together implicitly by making them adjacent to one another:
("This is the first line of my text, "
"which will be joined to a second.")
Or with line ending continuations, which is a little more fragile, as this works:
"This is the first line of my text, " \
"which wil...
What does the “map” method do in Ruby?
I'm new to programming. Can someone explain what .map would do in:
7 Answers
7
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What is the largest Safe UDP Packet Size on the Internet
...ving less fragments makes delivery "safer" because if there were more than one and any one of those never made it - the whole packet (datagram) is dropped by UDP.
– markmnl
Jan 5 '13 at 9:28
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How efficient can Meteor be while sharing a huge collection among many clients?
...allers register
callbacks for the same live query, the driver only watches one copy of
the query, calling each registered callback with the same result.
Each time the server updates a collection, the driver recalculates each
live query on that collection (Future versions of Meteor will expose a
sca...
Method chaining - why is it a good practice, or not?
... writing code easier (especially with IntelliSense). Mind you that this is one isolated case though, and is not a general practice in my code.
The point is - in 99% cases you can probably do just as well or even better without method chaining. But there is the 1% where this is the best approach.
...
How to change the foreign key referential action? (behavior)
...
Old question but adding answer so that one can get help
Its two step process:
Suppose, a table1 has a foreign key with column name fk_table2_id, with constraint name fk_name and table2 is referred table with key t2 (something like below in my diagram).
...
Using Python's os.path, how do I go up one directory?
I recently upgrade Django from v1.3.1 to v1.4.
14 Answers
14
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Python memoising/deferred lookup property decorator
Recently I've gone through an existing code base containing many classes where instance attributes reflect values stored in a database. I've refactored a lot of these attributes to have their database lookups be deferred, ie. not be initialised in the constructor but only upon first read. These attr...