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Getting a map() to return a list in Python 3.x
...atin-1 is to do bulk conversions at the C layer: bytes(sequence_of_ints_in_range_0_to_256).decode('latin-1') which makes a str faster by avoiding Python function calls for each element in favor of a bulk conversion of all elements using only C level function calls. You can wrap the above in list if ...
How do I write output in same place on the console?
... 'Downloading File FooFile.txt [%d%%]\r'%i,
Demo:
import time
for i in range(100):
time.sleep(0.1)
print 'Downloading File FooFile.txt [%d%%]\r'%i,
Python 3
print('Downloading File FooFile.txt [%d%%]\r'%i, end="")
Demo:
import time
for i in range(100):
time.sleep(0.1)
prin...
Stripping everything but alphanumeric chars from a string in Python
...the characters you wish to delete:
delchars = ''.join(c for c in map(chr, range(256)) if not c.isalnum())
(2) Whenever you want to scrunch a string:
scrunched = s.translate(None, delchars)
The setup cost probably compares favourably with re.compile; the marginal cost is way lower:
C:\junk>...
How do I decode HTML entities in Swift?
...p;' and copy the characters preceding it to `result`:
while let ampRange = self[position...].range(of: "&") {
result.append(contentsOf: self[position ..< ampRange.lowerBound])
position = ampRange.lowerBound
// Find the next ';' and copy everything ...
What does the “yield” keyword do?
...ou create a list, and so an iterable:
>>> mylist = [x*x for x in range(3)]
>>> for i in mylist:
... print(i)
0
1
4
Everything you can use "for... in..." on is an iterable; lists, strings, files...
These iterables are handy because you can read them as much as you wish, but y...
Python: fastest way to create a list of n lists
...
The probably only way which is marginally faster than
d = [[] for x in xrange(n)]
is
from itertools import repeat
d = [[] for i in repeat(None, n)]
It does not have to create a new int object in every iteration and is about 15 % faster on my machine.
Edit: Using NumPy, you can avoid the Pyt...
How to initialize a two-dimensional array in Python?
... [] \
for i in range (0, 10): \
new = [] \ can be replaced } this too
for j in range (0, 10): } with a list /
new.append(foo) / comprehension /
...
Any way to replace characters on Swift String?
...ring = aString.replacingOccurrences(of: " ", with: "+", options: .literal, range: nil)
And as noted by @cprcrack below, the options and range parameters are optional, so if you don't want to specify string comparison options or a range to do the replacement within, you only need the following.
le...
Nested classes' scope?
...ll
fail:
class A:
a = 42
b = list(a + i for i in range(10))
http://docs.python.org/reference/executionmodel.html#naming-and-binding
The above means:
a function body is a code block and a method is a function, then names defined out of the function body present in a...
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 ...