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Scala how can I count the number of occurrences in a list
...", "banana", "apple", "oranges", "oranges")
s.groupBy(identity).mapValues(_.size)
giving a Map with a count for each item in the original sequence:
Map(banana -> 1, oranges -> 3, apple -> 3)
The question asks how to find the count of a specific item. With this approach, the solution w...
Python nonlocal statement
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@Dustin - Actually, if you had class A with an attribute x and a subclass B defined in it, you would refer to x from within B as A.x
– Anon
Aug 11 '09 at 18:37
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Difference Between Cohesion and Coupling
... example of low cohesion at the top looks pretty good, I think you accidentally meant to say "high cohession"
– relipse
Mar 4 '16 at 14:45
39
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Writing Unicode text to a text file?
...a out of a Google doc, processing it, and writing it to a file (that eventually I will paste into a Wordpress page).
8 Answ...
How do I declare class-level properties in Objective-C?
...mething that's equivalent to a static variable? E.g. only one instance for all types of Foo?
To declare class functions in Objective-C you use the + prefix instead of - so your implementation would look something like:
// Foo.h
@interface Foo {
}
+ (NSDictionary *)dictionary;
// Foo.m
+ (NSDicti...
Python argparse: Make at least one argument required
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args = vars(parser.parse_args())
if not any(args.values()):
parser.error('No arguments provided.')
share
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improve this answer
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Explicitly select items from a list or tuple
... myBigList[i] for i in [87, 342, 217, 998, 500] ]
20.6 usec: map(myBigList.__getitem__, (87, 342, 217, 998, 500))
22.7 usec: itemgetter(87, 342, 217, 998, 500)(myBigList)
24.6 usec: list( myBigList[i] for i in [87, 342, 217, 998, 500] )
Note that in Python 3, the 1st was changed to be the same as ...
How to generate keyboard events in Python?
...om ctypes import wintypes
import time
user32 = ctypes.WinDLL('user32', use_last_error=True)
INPUT_MOUSE = 0
INPUT_KEYBOARD = 1
INPUT_HARDWARE = 2
KEYEVENTF_EXTENDEDKEY = 0x0001
KEYEVENTF_KEYUP = 0x0002
KEYEVENTF_UNICODE = 0x0004
KEYEVENTF_SCANCODE = 0x0008
MAPVK_VK_TO_VSC = 0
# ...
How to read a file in reverse order?
...A correct, efficient answer written as a generator.
import os
def reverse_readline(filename, buf_size=8192):
"""A generator that returns the lines of a file in reverse order"""
with open(filename) as fh:
segment = None
offset = 0
fh.seek(0, os.SEEK_END)
file...
Finding local maxima/minima with Numpy in a 1D numpy array
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If you are looking for all entries in the 1d array a smaller than their neighbors, you can try
numpy.r_[True, a[1:] < a[:-1]] & numpy.r_[a[:-1] < a[1:], True]
You could also smooth your array before this step using numpy.convolve().
I...