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How to optimize for-comprehensions and loops in Scala?
...higher-order methods; in this case, you're calling the foreach method on a Range object. Scala's for is very general, but sometimes leads to painful performance.
You might want to try the -optimize flag in Scala version 2.9. Observed performance may depend on the particular JVM in use, and the JIT ...
How do I get the number of elements in a list?
...he builtin function, len:
items = []
items.append("apple")
items.append("orange")
items.append("banana")
And now:
len(items)
returns 3.
Explanation
Everything in Python is an object, including lists. All objects have a header of some sort in the C implementation.
Lists and other similar bu...
How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops
...workbook.
Click "OK"
Step 2: Define your pattern
Basic definitions:
- Range.
E.g. a-z matches an lower case letters from a to z
E.g. 0-5 matches any number from 0 to 5
[] Match exactly one of the objects inside these brackets.
E.g. [a] matches the letter a
E.g. [abc] matches a single le...
Is it better to use std::memcpy() or std::copy() in terms to performance?
...ke this work by first working on the unaligned portion at the start of the range, then the aligned portion, then the unaligned portion at the end. If it is all guaranteed to be aligned, then the code becomes simpler and faster, and easier for the branch predictor in your processor to get correct.
P...
What is the most “pythonic” way to iterate over a list in chunks?
...
def chunker(seq, size):
return (seq[pos:pos + size] for pos in range(0, len(seq), size))
# (in python 2 use xrange() instead of range() to avoid allocating a list)
Works with any sequence:
text = "I am a very, very helpful text"
for group in chunker(text, 7):
print(repr(group),)
# '...
SQlite Getting nearest locations (with latitude and longitude)
...picture).
/**
* Calculates the end-point from a given source at a given range (meters)
* and bearing (degrees). This methods uses simple geometry equations to
* calculate the end-point.
*
* @param point
* Point of origin
* @param range
* Range in meters
* @param bearing
* ...
Generating random whole numbers in JavaScript in a specific range?
...instead of Math.floor() converts x into a two-complement with much smaller range than Number.MAX_SAFE_INTEGER (2³²⁻¹ vs. 2⁵³), thus you have to use it with caution!
– le_m
Jun 6 '16 at 1:49
...
Python time measure function
...Timer
@Timer(average=False)
def matmul(a,b, times=100):
for i in range(times):
np.dot(a,b)
Output:
matmul:0.368434
matmul:2.839355
It can also work like a plug-in timer with namespace control(helpful if you are inserting it to a function which has a lot of codes and ma...
Create tap-able “links” in the NSAttributedString of a UILabel?
...butedString alloc] initWithString:@"String with a link" attributes:nil];
NSRange linkRange = NSMakeRange(14, 4); // for the word "link" in the string above
NSDictionary *linkAttributes = @{ NSForegroundColorAttributeName : [UIColor colorWithRed:0.05 green:0.4 blue:0.65 alpha:1.0],
...
Lazy Method for Reading Big File in Python?
..._row(chunksize=1024):
with open(test_file, 'w') as f:
for i in range(1025):
f.write('a')
with open(test_file) as f:
assert len(list(rows(f, chunksize=chunksize))) == 1
@cleanup
def test_1024_chars_2_rows(chunksize=1024):
with open(test_file, 'w') as f:
...