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Referring to the null object in Python
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SyntaxError: cannot assign to keyword
It's therefore safe to assume that all None references are the same. There isn't any "custom" None.
To test for None use the is operator
When writing code you might be tempted to test for Noneness like this:
if value==None:
pass
Or to test for falsehood l...
How to limit the maximum value of a numeric field in a Django model?
...ormer can be restricted to the number of decimal places stored and the overall number of characters stored, is there any way to restrict it to storing only numbers within a certain range, e.g. 0.0-5.0 ?
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Pelican 3.3 pelican-quickstart error “ValueError: unknown locale: UTF-8”
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You could try a solution posted here or here. Basically, add some lines to your ~/.bash_profile:
export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8
There is an outstanding bug report related to this issue. It appears that Python makes some assumptions about the format of l...
Functional programming - is immutability expensive? [closed]
...’d like to clarify some points.
The “in-place” quicksort isn’t really in-place (and quicksort is not by definition in-place). It requires additional storage in the form of stack space for the recursive step, which is in the order of O(log n) in the best case, but O(n) in the worst case.
Im...
How can I start PostgreSQL server on Mac OS X?
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The Homebrew package manager includes launchctl plists to start automatically. For more information, run brew info postgres.
Start manually
pg_ctl -D /usr/local/var/postgres start
Stop manually
pg_ctl -D /usr/local/var/postgres stop
Start automatically
"To have launchd start postgresql now and res...
How to merge YAML arrays?
...hon:3.7.3
stage: test
script:
- *pip_git
- pip install -q -r requirements_test.txt
- python -m unittest discover tests
use the same `*pip_git` on e.g. build image...
where requirements_test.txt contains e.g.
-e git+ssh://git@gitlab.com/example/example.git@v0.2.2#e...
Easiest way to convert int to string in C++
...icking up a discussion with @v.oddou a couple of years later, C++17 has finally delivered a way to do the originally macro-based type-agnostic solution (preserved below) without going through macro uglyness.
// variadic template
template < typename... Args >
std::string sstr( Args &&....
Converting JavaScript object with numeric keys into array
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It's actually very straight forward with jQuery's $.map
var arr = $.map(obj, function(el) { return el });
FIDDLE
and almost as easy without jQuery as well, converting the keys to an array and then mapping back the values with Arra...
Javascript sort array by two fields
...iot proof - but doesn't seem necessary.
function getSortMethod(){
var _args = Array.prototype.slice.call(arguments);
return function(a, b){
for(var x in _args){
var ax = a[_args[x].substring(1)];
var bx = b[_args[x].substring(1)];
var cx;
...
Can't find the 'libpq-fe.h header when trying to install pg gem
...on Rails 3.1 pre version. I like to use PostgreSQL, but the problem is installing the pg gem. It gives me the following error:
...