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Append an object to a list in R in amortized constant time, O(1)?
... 2-element vector named c as is clearly intended!
– j_random_hacker
Dec 5 '11 at 16:45
7
So is th...
How to find out which package version is loaded in R?
...plish that.
> sessionInfo()
R version 2.15.0 (2012-03-30)
Platform: x86_64-pc-linux-gnu (64-bit)
locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
[5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 LC_PAPER=C ...
Try catch statements in C
...ou can simulate them to a degree with setjmp and longjmp calls.
static jmp_buf s_jumpBuffer;
void Example() {
if (setjmp(s_jumpBuffer)) {
// The longjmp was executed and returned control here
printf("Exception happened here\n");
} else {
// Normal code execution starts here
Te...
sql “LIKE” equivalent in django query
...
Use __contains or __icontains (case-insensitive):
result = table.objects.filter(string__contains='pattern')
The SQL equivalent is
SELECT ... WHERE string LIKE '%pattern%';
...
Extract substring in Bash
Given a filename in the form someletters_12345_moreleters.ext , I want to extract the 5 digits and put them into a variable.
...
Running unittest with typical test directory structure
...e TestLoader class).
For example for a directory structure like this:
new_project
├── antigravity.py
└── test_antigravity.py
You can just run:
$ cd new_project
$ python -m unittest test_antigravity
For a directory structure like yours:
new_project
├── antigravity
│ ...
How to run code when a class is subclassed? [duplicate]
...on2 you would define the metaclass of a class with
class SuperClass:
__metaclass__ = Watcher
where Watcher is a subclass of type.
In Python3 the syntax has been changed to
class SuperClass(metaclass=Watcher)
Both are equivalent to
Superclass = Watcher(name, bases, clsdict)
where in t...
Is there an expression for an infinite generator?
...te itertools.count: count = lambda start=0, step=1: (start + i*step for i, _ in enumerate(iter(int, 1)))
– Coffee_Table
Aug 13 '18 at 23:43
2
...
Repeat string to certain length
...
def repeat_to_length(string_to_expand, length):
return (string_to_expand * ((length/len(string_to_expand))+1))[:length]
For python3:
def repeat_to_length(string_to_expand, length):
return (string_to_expand * (int(length/len(s...
Re-raise exception with a different type and message, preserving existing information
...ble to whatever code catches the new exception.
By using this feature, the __cause__ attribute is set. The built-in exception handler also knows how to report the exception's “cause” and “context” along with the traceback.
In Python 2, it appears this use case has no good answer (as describ...