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Iterator Loop vs index loop [duplicate]
...trides (unless you use an iterator adapter that overloads operator++).
4) range-for loop
for (auto& elem: v) {
// if the current index is needed:
auto i = &elem - &v[0];
// any code including continue, break, return
}
Advantages: very compact loop control, direct acces...
JSON formatter in C#?
... sb.AppendLine();
Enumerable.Range(0, ++indent).ForEach(item => sb.Append(INDENT_STRING));
}
break;
case '}':
case ']':
if (!quoted)
{
...
RE error: illegal byte sequence on Mac OS X
...ly recognize basic English letters as letters (the ones in the 7-bit ASCII range), so that foreign chars. will not be treated as letters, causing, for instance, upper-/lowercase conversions to fail.
Again, this may be fine if you needn't match multibyte-encoded characters such as é, and simply wan...
Why is iterating through a large Django QuerySet consuming massive amounts of memory?
... # change this to desired chunk size
for page in range(1, paginator.num_pages + 1):
for row in paginator.page(page).object_list:
# here you can do whatever you want with the row
print "done processing page %s" % page
...
How do I check if there are duplicates in a flat list?
...uplicate run
@b.add_arguments('list size')
def arguments():
for exp in range(2, 14):
size = 2**exp
yield size, list(range(size))
# Duplicate at beginning run
@b.add_arguments('list size')
def arguments():
for exp in range(2, 14):
size = 2**exp
yield size, [0,...
What is the optimal Jewish toenail cutting algorithm?
...lements 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]
if abs(a-b) == 1:
return False
return True
from itertools import ifilter, permutations
validseqs = ifilter(isValid, permutations([1,2,3,4,5]...
Python: changing value in a tuple
...ples (on Python 3.3), concatenation is actually faster!
In [3]: d = tuple(range(10))
In [4]: %timeit replace_at_index1(d, 5, 99)
1000000 loops, best of 3: 872 ns per loop
In [5]: %timeit replace_at_index2(d, 5, 99)
1000000 loops, best of 3: 642 ns per loop
Yet if we look at longer tuples, list ...
Is there a replacement for unistd.h for Windows (Visual C)?
...a
* common MinGW API in libmingwex.a, providing for suspension periods
* ranging from mean values of ~7.5 milliseconds, (see the comments in
* <time.h>), extending up to a maximum of ~136 years.
*
* Note that, whereas POSIX supports early wake-up of any suspended
* process/thread, in res...
How do I determine k when using k-means clustering?
...klearn.cluster import KMeans
from sklearn.metrics import silhouette_score
range_n_clusters = [2, 3, 4] # clusters range you want to select
dataToFit = [[12,23],[112,46],[45,23]] # sample data
best_clusters = 0 # best cluster number which you will get
previous_silh_...
How do I use IValidatableObject?
...idatableObject
{
[Required]
public bool Enable { get; set; }
[Range(1, 5)]
public int Prop1 { get; set; }
[Range(1, 5)]
public int Prop2 { get; set; }
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
var results = n...