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How do Python's any and all functions work?
... entire iterable need not be consumed. For example,
>>> multiples_of_6 = (not (i % 6) for i in range(1, 10))
>>> any(multiples_of_6)
True
>>> list(multiples_of_6)
[False, False, False]
Here, (not (i % 6) for i in range(1, 10)) is a generator expression which returns Tru...
Unable to install Maven on Windows: “JAVA_HOME is set to an invalid directory”
...e-maven-2.2.0\bin" is on your command search path.
Make sure that the JAVA_HOME variable refers to the home directory for your Java installation. If you are executing Java from "E:\Sun\SDK\jdk\bin", then the JAVA_HOME variable needs to point to "E:\Sun\SDK\jdk".
NB: JAVA_HOME should NOT end with "...
Function for Factorial in Python
...The concept used here is called recursion ( en.wikipedia.org/wiki/Recursion_(computer_science) ) - a function calling itself is perfectly fine and often useful.
– schnaader
Nov 7 '14 at 10:06
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SQLAlchemy: cascade delete
... This is well explained in the current doc docs.sqlalchemy.org/en/rel_0_9/orm/cascades.html
– Epoc
Feb 28 '15 at 19:47
1
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Scala @ operator
...n itself? That would be accomplished with this:
o match {
case x @ Some(_) => println(x)
case None =>
}
Note that @ can be used at any level, not just at the top level of the matching.
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Chrome, Javascript, window.open in new tab
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As of 9/29/2014, latest Firefox ESR and IE 11 open _blank or window.open links in a new window when the js calls use _blank as the window name. Current Chrome isn't that simple. I tested opening a new window passing top, left, width, height, toolbar, location, directories, st...
Calling parent class __init__ with multiple inheritance, what's the right way?
...s to greater flexibility for subclasses.
In the direct call approach, C.__init__ can call both A.__init__ and B.__init__.
When using super(), the classes need to be designed for cooperative multiple inheritance where C calls super, which invokes A's code which will also call super which invokes ...
Get fully qualified class name of an object in Python
...lowing program
#! /usr/bin/env python
import foo
def fullname(o):
# o.__module__ + "." + o.__class__.__qualname__ is an example in
# this context of H.L. Mencken's "neat, plausible, and wrong."
# Python makes no guarantees as to whether the __module__ special
# attribute is defined, so we...
#1071 - Specified key was too long; max key length is 1000 bytes
...per column as you define the index. For example:
...
KEY `index` (`parent_menu_id`,`menu_link`(50),`plugin`(50),`alias`(50))
...
But what's the best prefix length for a given column? Here's a method to find out:
SELECT
ROUND(SUM(LENGTH(`menu_link`)<10)*100/COUNT(`menu_link`),2) AS pct_leng...
Sort hash by key, return hash in Ruby
...
In Ruby 2.1 it is simple:
h.sort.to_h
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