大约有 47,000 项符合查询结果（耗时：0.0418秒） [XML]
PHP: merge two arrays while keeping keys instead of reindexing?
...
You can simply 'add' the arrays:
>> $a = array(1, 2, 3);
array (
0 => 1,
1 => 2,
2 => 3,
)
>> $b = array("a" => 1, "b" => 2, "c" => 3)
array (
'a' => 1,
'b' => 2,
'c' => 3,
)
>> $a + $b
array (
0 => 1,
1 => 2,
2 ...
Numpy: Divide each row by a vector element
...
answered Oct 26 '13 at 2:38
JoshAdelJoshAdel
53.3k2222 gold badges125125 silver badges126126 bronze badges
...
efficient circular buffer?
...
206
I would use collections.deque with a maxlen arg
>>> import collections
>>> ...
What is the optimal Jewish toenail cutting algorithm?
...le. Luckily, humans only have five toes per foot*, so there are only 5! = 120 unrestricted sequences.
Python example:
#seq is only valid when consecutive elements in the list differ by at least two.
def isValid(seq):
for i in range(len(seq)-1):
a = seq[i]
b = seq[i+1]
...
How to trace the path in a Breadth-First Search?
...aths.
# graph is in adjacent list representation
graph = {
'1': ['2', '3', '4'],
'2': ['5', '6'],
'5': ['9', '10'],
'4': ['7', '8'],
'7': ['11', '12']
}
def bfs(graph, start, end):
# maintain a queue of paths
queue = []
# push the first p...
Pandas dataframe get first row of each group
...
248
>>> df.groupby('id').first()
value
id
1 first
2 first
3 first
4...
What is the significance of initializing direction arrays below with given values when developing ch
...what move each index of the arrays will make from the central point, X, at 2,2.)
.....
.536.
.1X0.
.724.
.....
The way it is set up, if you do ^1 (^ being bitwise XOR) on the index you get the opposite direction - 0 and 1 are opposites, 2 and 3 are opposites and so on. (Another way to set it up i...
No secret option provided to Rack::Session::Cookie warning?
I am running Rails 3.2.3, Ruby 1.9 under Fedora 17. I get this warning, when I run rails s , and how do I fix?
7 Answers
...
Find the max of two or more columns with pandas
...
2 Answers
2
Active
...
Python creating a dictionary of lists
...
286
You can use defaultdict:
>>> from collections import defaultdict
>>> d = de...