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Python group by
...
Python's built-in itertools module actually has a groupby function , but for that the elements to be grouped must first be sorted such that the elements to be grouped are contiguous in the list:
from operator import itemgetter
sortkeyfn = itemgetter(1)
input = [(...
How do I lock the orientation to portrait mode in a iPhone Web Application?
...elopment-for-the-iphone/
However...
Apple's approach to this issue is to allow the developer to change the CSS based on the orientation change but not to prevent re-orientation completely. I found a similar question elsewhere:
http://ask.metafilter.com/99784/How-can-I-lock-iPhone-orientation-in-M...
How do I make class methods / properties in Swift?
...
They are called type properties and type methods and you use the class or static keywords.
class Foo {
var name: String? // instance property
static var all = [Foo]() // static type property
class var comp: In...
What is a JavaBean exactly?
...
A JavaBean is just a standard
All properties private (use getters/setters)
A public no-argument constructor
Implements Serializable.
That's it. It's just a convention. Lots of libraries depend on it though.
With respect to Serializable, from the API d...
Makefile经典教程（入门必备） - C/C++ - 清泛网移动版 - 专注C/C++及内核技术
...定义的值。如：
foo = $(bar)
bar = $(ugh)
ugh = Huh?
all:
echo $(foo)
我们执行“make all”将会打出变量$(foo)的值是“Huh?”（ $(foo)的值是$(bar)，$(bar)的值是$(ugh)，$(ugh)的值是“Huh?”）可见，变量是可以使用后面的变量来...
Hashing a file in Python
...those bigger files in chunks!
import sys
import hashlib
# BUF_SIZE is totally arbitrary, change for your app!
BUF_SIZE = 65536 # lets read stuff in 64kb chunks!
md5 = hashlib.md5()
sha1 = hashlib.sha1()
with open(sys.argv[1], 'rb') as f:
while True:
data = f.read(BUF_SIZE)
i...
Restore the state of std::cout after manipulating it
...lude <iostream> or #include <ios> then when required:
std::ios_base::fmtflags f( cout.flags() );
//Your code here...
cout.flags( f );
You can put these at the beginning and end of your function, or check out this answer on how to use this with RAII.
...
force Maven to copy dependencies into target/lib
...tions>
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${proj...
How to write a multidimensional array to a text file?
...is specified by the comments kwarg). (This looks more verbose than it actually is...)
import numpy as np
# Generate some test data
data = np.arange(200).reshape((4,5,10))
# Write the array to disk
with open('test.txt', 'w') as outfile:
# I'm writing a header here just for the sake of readabil...
What are the differences between virtual memory and physical memory?
...e (in case of other implementations of virtual memory, we maybe shouldn't call it the "page table"). The page table is in physical memory as well - often in kernel-reserved spaces that user programs cannot write over.
Virtual memory is typically larger than physical memory - there wouldn't be much ...