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Python Dictionary Comprehension
...t; d = {n: n**2 for n in range(5)}
>>> print d
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16}
If you want to set them all to True:
>>> d = {n: True for n in range(5)}
>>> print d
{0: True, 1: True, 2: True, 3: True, 4: True}
What you seem to be asking for is a way to set multiple ke...
Apply pandas function to column to create multiple new columns?
...
13 Answers
13
Active
...
How does PHP 'foreach' actually work?
...ction iterate($arr) {
foreach ($arr as $v) {}
}
$outerArr = [0, 1, 2, 3, 4];
iterate($outerArr);
Here, $arr will be duplicated to prevent IAP changes on $arr from leaking to $outerArr. In terms of the conditions above, the array is not a reference (is_ref=0) and is used in two places (refcoun...
What's the fastest way to merge/join data.frames in R?
...
DF1 = data.frame(a = c(1, 1, 2, 2), b = 1:4)
DF2 = data.frame(b = c(1, 2, 3, 3, 4), c = letters[1:5])
merge(DF1, DF2)
b a c
1 1 1 a
2 2 1 b
3 3 2 c
4 3 2 d
5 4 2 e
DF1$c = DF2$c[match(DF1$b, DF2$b)]
DF1$c
[1] a b c e
Levels: a b c d e
> DF1
a b c
1 1 1 a
2 1 2 b
3 2 3 c
4 2 4 e
...
Algorithm for Determining Tic Tac Toe Game Over
...
133
You know a winning move can only happen after X or O has made their most recent move, so you ca...
What is the difference between Python's list methods append and extend?
...
5329
append: Appends object at the end.
x = [1, 2, 3]
x.append([4, 5])
print (x)
gives you: [1, ...
Obfuscated C Code Contest 2006. Please explain sykes2.c
...g:
main(_) {
_^448 && main(-~_);
putchar(--_%64
? 32 | -~7[__TIME__-_/8%8][">'txiZ^(~z?"-48] >> ";;;====~$::199"[_*2&8|_/64]/(_&2?1:8)%8&1
: 10);
}
Introducing variables to untangle this mess:
main(int i) {
if(i^448)
main(-~i);
...
Python dictionary: Get list of values for list of keys
...
213
A list comprehension seems to be a good way to do this:
>>> [mydict[x] for x in mykeys...
Generate random int value from 3 to 6
...ossible in Microsoft SQL Server generate random int value from Min to Max (3-9 example, 15-99 e.t.c)
10 Answers
...
What does the “map” method do in Ruby?
...
432
The map method takes an enumerable object and a block, and runs the block for each element, out...