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List of lists changes reflected across sublists unexpectedly
...o it:
x = [1] * 4
l = [x] * 3
print(f"id(x): {id(x)}")
# id(x): 140560897920048
print(
f"id(l[0]): {id(l[0])}\n"
f"id(l[1]): {id(l[1])}\n"
f"id(l[2]): {id(l[2])}"
)
# id(l[0]): 140560897920048
# id(l[1]): 140560897920048
# id(l[2]): 140560897920048
x[0] = 42
print(f"x: {x}")
# x: [42, ...
How can I check if a key exists in a dictionary? [duplicate]
Let's say I have an associative array like so: {'key1': 22, 'key2': 42} .
3 Answers
3...
Can I change the checkbox size using CSS?
...type=checkbox]
{
/* Double-sized Checkboxes */
-ms-transform: scale(2); /* IE */
-moz-transform: scale(2); /* FF */
-webkit-transform: scale(2); /* Safari and Chrome */
-o-transform: scale(2); /* Opera */
transform: scale(2);
padding: 10px;
}
/* Might want to wrap a span ar...
Google Maps API 3 - Custom marker color for default (dot) marker
...urls:
http://chart.apis.google.com/chart?chst=d_map_pin_letter&chld=%E2%80%A2|FE7569
Which looks like this: the image is 21x34 pixels and the pin tip is at position (10, 34)
And you'll also want a separate shadow image (so that it doesn't overlap nearby icons):
http://chart.apis.google.com...
How to concatenate properties from multiple JavaScript objects
...ject.
MDN documentation on Object.assign()
var o1 = { a: 1 };
var o2 = { b: 2 };
var o3 = { c: 3 };
var obj = Object.assign({}, o1, o2, o3);
console.log(obj); // { a: 1, b: 2, c: 3 }
Object.assign is supported in many modern browsers but not yet all of them. Use a transpiler like...
What's the difference between “version number” in iTunes Connect, “bundle version”, “bundle version
...n number shown in the App Store; This must be a pure version number like 1.2.3
Bundle Version (CFBundleVersion)
This doesn't need to be a pure version number. This can be something like 12345 or 1.2.3 (Build 12345AB). This is shown in the About window for Mac OS X apps for example and is often mor...
What are best practices for validating email addresses on iOS 2.0
...is the cleanest way to validate an email address that a user enters on iOS 2.0?
13 Answers
...
What does “SyntaxError: Missing parentheses in call to 'print'” mean in Python?
...to use Python 3 to follow an example or run a program that uses the Python 2 print statement:
print "Hello, World!"
The statement above does not work in Python 3. In Python 3 you need to add parentheses around the value to be printed:
print("Hello, World!")
“SyntaxError: Missing parent...