extend

问题 This question already has answers here : Why does list.append evaluate to false in a boolean context? [duplicate] (7 answers) Closed 3 years ago . Why does python 2.5.2 have the following behavior >>>[2].extend([]) == [2] False >>> [2].extend([]) == None True $ python --version Python 2.5.2 I assume I\'m not understanding something here, but intuitively I\'d think that [2].extend([]) should yield [2] 回答1: Extend is a method of list, which modifies it but doesn't return self (returning None

问题 I am trying to write a plugin that will extend an existing function in jQuery, e.g. (function($) { $.fn.css = function() { // stuff I will be extending // that doesn\'t affect/change // the way .css() works }; })(jQuery); There are only a few bits I need to extend of the .css() function. Mind me for asking, I was thinking about PHP classes since you can className extend existingClass , so I\'m asking if it\'s possible to extend jQuery functions. 回答1: Sure... Just save a reference to the

问题 SASS has a feature called @extend which allows a selector to inherit the properties of another selector, but without copying the properties (like mixins). Does LESS have this feature as well? 回答1: Yes, Less.js introduced extend in v1.4.0. :extend() Rather than implementing the at-rule ( @extend ) syntax used by SASS and Stylus, LESS implemented the pseudo-class syntax, which gives LESS's implementation the flexibility to be applied either directly to a selector itself, or inside a statement.

问题 Given two lists: x = [1,2,3] y = [4,5,6] What is the syntax to: Insert x into y such that y now looks like [1, 2, 3, [4, 5, 6]] ? Insert all the items of x into y such that y now looks like [1, 2, 3, 4, 5, 6] ? 回答1: Do you mean append ? >>> x = [1,2,3] >>> y = [4,5,6] >>> x.append(y) >>> x [1, 2, 3, [4, 5, 6]] Or merge? >>> x = [1,2,3] >>> y = [4,5,6] >>> x + y [1, 2, 3, 4, 5, 6] >>> x.extend(y) >>> x [1, 2, 3, 4, 5, 6] 回答2: The question does not make clear what exactly you want to achieve.

问题 Just getting my head around Ruby metaprogramming. The mixin/modules always manage to confuse me. include : mixes in specified module methods as instance methods in the target class extend : mixes in specified module methods as class methods in the target class So is the major difference just this or is a bigger dragon lurking? e.g. module ReusableModule def module_method puts \"Module Method: Hi there!\" end end class ClassThatIncludes include ReusableModule end class ClassThatExtends extend

问题 I\'m a fairly new jQuery user looking to extend an existing jQuery plugin that does about 75% of what I need. I\'ve tried to do my homework on this. I\'ve checked out the following questions on stackoverflow: Extending a jQuery Plugin Extend a jQuery Plugin jQuery: extend plugin question I\'ve read up on the extend method. However, all of thise homework has left me confused. I\'m working with the fullcalendar plugin and need to modify some of the behavior as well as add new event hooks. Am I

问题 I\'ve done some reading about how to extend ActiveRecord:Base class so my models would have some special methods. What is the easy way to extend it (step by step tutorial)? 回答1: There are several approaches : Using ActiveSupport::Concern (Preferred) Read the ActiveSupport::Concern documentation for more details. Create a file called active_record_extension.rb in the lib directory. require 'active_support/concern' module ActiveRecordExtension extend ActiveSupport::Concern # add your instance

问题 This post is a Community Wiki . Edit existing answers to improve this post. It is not currently accepting new answers. What\'s the difference between the list methods append() and extend() ? 回答1: append: Appends object at the end. x = [1, 2, 3] x.append([4, 5]) print (x) gives you: [1, 2, 3, [4, 5]] extend: Extends list by appending elements from the iterable. x = [1, 2, 3] x.extend([4, 5]) print (x) gives you: [1, 2, 3, 4, 5] 回答2: append adds an element to a list, and extend concatenates the