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What's the difference between lists enclosed by square brackets and parentheses in Python?
...1, 2)
>>> x.append(3)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'tuple' object has no attribute 'append'
The other main difference is that a tuple is hashable, meaning that you can use it as a key to a dictionary, among other thin...
UML class diagram enum
...
They are simply showed like this:
_______________________
| <<enumeration>> |
| DaysOfTheWeek |
|_____________________|
| Sunday |
| Monday |
| Tuesday |
| ... |
|_____________________|
And then just have an as...
How to access custom attributes from event object in React?
...perhaps a different way than you asked:
render: function() {
...
<a data-tag={i} style={showStyle} onClick={this.removeTag.bind(null, i)}></a>
...
},
removeTag: function(i) {
// do whatever
},
Notice the bind(). Because this is all javascript, you can do handy things l...
How to compare two colors for similarity/difference
...don't know how to do that manually step by step. So it is even more difficult to think of a program.
19 Answers
...
make arrayList.toArray() return more specific types
...
Like this:
List<String> list = new ArrayList<String>();
String[] a = list.toArray(new String[0]);
Before Java6 it was recommended to write:
String[] a = list.toArray(new String[list.size()]);
because the internal implementa...
In Python, how do I determine if an object is iterable?
...ake = Faker()
>>> iter(fake) # No exception, must be iterable
<iterator object at 0x7f1c71db58d0>
>>> list(fake) # Ooops
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/.../site-packages/faker/proxy.py", line 59, in __g...
Integrating the ZXing library directly into my Android application
...
Here is an ImageView element to add to your Activity layout XML file:
<ImageView
android:id="@+id/qrCode"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="50dp"
android:layout_centerHorizontal="true"/>
Code snippet:
...
Who architected / designed C++'s IOStreams, and would it still be considered well-designed by today'
...al ill-conceived ideas found their way into the standard: auto_ptr, vector<bool>, valarray and export, just to name a few. So I wouldn't take the presence of IOStreams necessarily as a sign of quality design.
IOStreams have a checkered history. They are actually a reworking of an earlier stre...
One line if statement not working
... Ruby:
@item.rigged? ? 'Yes' : 'No'
It's simply hard to read with the multiple question marks that close to each other.
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How to have stored properties in Swift, the same way I had on Objective-C?
...the boilerplate with a helper class.
public final class ObjectAssociation<T: AnyObject> {
private let policy: objc_AssociationPolicy
/// - Parameter policy: An association policy that will be used when linking objects.
public init(policy: objc_AssociationPolicy = .OBJC_ASSOCIATI...