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Some built-in to pad a list in python
...
a += [''] * (N - len(a))
or if you don't want to change a in place
new_a = a + [''] * (N - len(a))
you can always create a subclass of list and call the method whatever you please
class MyList(list):
def ljust(self, n, fillvalue=''):
return self + [fillvalue] * (n - len(self))
a...
Mediator Vs Observer Object-Oriented Design Patterns
...o has access to it)
function Person(name) {
let self = this;
this._name = name;
this._chat = null;
this._receive(from, message) {
console.log("{0}: '{1}'".format(from.name(), message));
}
this._send(to, message) {
this._chat.message(this, to, message...
How to disable HTML button using JavaScript?
...n purposes
// don't ever actually use document.write(), eval(), or access __proto__
function log(value) {
document.write(`<pre>${value}</pre>`);
}
function logChain(code) {
log(code);
var object = eval(code);
do {
log(`${object.constructor.name} ${object instan...
Reverse a string in Python
... for readability and reusability, put the slice in a function
def reversed_string(a_string):
return a_string[::-1]
and then:
>>> reversed_string('a_string')
'gnirts_a'
Longer explanation
If you're interested in the academic exposition, please keep reading.
There is no built-i...
How to force link from iframe to be opened in the parent window
...Add the following to the head of the page in the iframe:
<base target="_parent">
This will load all links on the page in the parent window. If you want your links to load in a new window, use:
<base target="_blank">
This tag is fully supported in all browsers.
...
HTML5 Local Storage fallback solutions [closed]
...Gears-based persistent storage.
localstorage: HTML5 draft storage.
whatwg_db: HTML5 draft database storage.
globalstorage: HTML5 draft storage (old spec).
ie: Internet Explorer userdata behaviors.
cookie: Cookie-based persistent storage.
Any of those can be disabled—if, for example, you don...
ViewPager and fragments — what's the right way to store fragment's state?
... onCreate(Bundle savedInstanceState) {
setContentView(R.layout.activity_main);
if (savedInstanceState != null)
viewpagerid=savedInstanceState.getInt("viewpagerid", -1 );
MyFragmentPagerAdapter titleAdapter = new MyFragmentPagerAdapter (getSupportFragmentManager() , this); ...
Apply multiple functions to multiple groupby columns
...ame, you can use a normal function and supply a custom name to the special __name__ attribute like this:
def max_min(x):
return x.max() - x.min()
max_min.__name__ = 'Max minus Min'
df.groupby('group').agg({'a':['sum', 'max'],
'b':'mean',
'c'...
Using Django time/date widgets in custom form
... the proper field names from your model):
from django import forms
from my_app.models import Product
from django.contrib.admin import widgets
class ProductForm(forms.ModelForm):
class Meta:
model = Product
def __init__(self, *args, **kwargs):
...
Scala equivalent of Java java.lang.Class Object
...: java.lang.Class[C] = class C
scala> c.getClass
res1: java.lang.Class[_] = class C
That is why the following will not work:
val xClass: Class[X] = new X().getClass //it returns Class[_], nor Class[X]
val integerClass: Class[Integer] = new Integer(5).getClass //similar error
There is a ticket...