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What __init__ and self do on Python?
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In this code:
class A(object):
def __init__(self):
self.x = 'Hello'
def method_a(self, foo):
print self.x + ' ' + foo
... the self variable represents the instance of the object itself. Most object-oriented languages pass this as a hidd...
Simple way to encode a string according to a password?
...asual observer, and you aren't looking to use third party libraries. I'd recommend something like the Vigenere cipher. It is one of the strongest of the simple ancient ciphers.
Vigenère cipher
It's quick and easy to implement. Something like:
import base64
def encode(key, string):
encoded_c...
Is there a MySQL option/feature to track history of changes to records?
...ld vs new is available and the date this took place. Is there a feature or common technique to do this?
8 Answers
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Check if an image is loaded (no errors) with jQuery
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Check the complete and naturalWidth properties, in that order.
https://stereochro.me/ideas/detecting-broken-images-js
function IsImageOk(img) {
// During the onload event, IE correctly identifies any images that
// weren’t downloaded as not complete. Others should too. Gecko-b...
Postgres could not connect to server
...s upgrade.
In my case, it happened when upgrading from 9.3 to 9.4.
See http://www.postgresql.org/docs/9.4/static/upgrading.html
OS X/Homebrew:
Try running postgres -D /usr/local/var/postgres -- it will give you a much more verbose output if postgres fails to start.
In my case, running rm -rf ...
Standard alternative to GCC's ##__VA_ARGS__ trick?
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It is possible to avoid the use of GCC's ,##__VA_ARGS__ extension if you are willing to accept some hardcoded upper limit on the number of arguments you can pass to your variadic macro, as described in Richard Hansen's answer to this question. If you do not want to hav...
Calling class staticmethod within the class body?
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staticmethod objects apparently have a __func__ attribute storing the original raw function (makes sense that they had to). So this will work:
class Klass(object):
@staticmethod # use as decorator
def stat_func():
return 42
_ANS = stat_func...
How does the @property decorator work in Python?
...is just syntactic sugar; the syntax:
@property
def foo(self): return self._foo
really means the same thing as
def foo(self): return self._foo
foo = property(foo)
so foo the function is replaced by property(foo), which we saw above is a special object. Then when you use @foo.setter(), what you ...
SQL Server SELECT INTO @variable?
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Sounds like you want temp tables.
http://www.sqlteam.com/article/temporary-tables
Note that #TempTable is available throughout your SP.
Note the ##TempTable is available to all.
sha...
What is the difference between `-fpic` and `-fPIC` gcc parameters?
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http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html
Use -fPIC or -fpic to generate position independent code. Whether to use -fPIC or -fpic to generate position independent code is target-dependent. The -fPIC ...