大约有 7,000 项符合查询结果（耗时：0.0278秒） [XML]
Why is “if not someobj:” better than “if someobj == None:” in Python?
... to False.
This is the "magic" behind short circuiting expressions like:
foo = bar and spam or eggs
which is shorthand for:
if bar:
foo = spam
else:
foo = eggs
although you really should write:
foo = spam if bar else egg
...
How to show git log history for a sub directory of a git repo?
...
From directory foo/, use
git log -- A
You need the '--' to separate <path>.. from the <since>..<until> refspecs.
# Show changes for src/nvfs
$ git log --oneline -- src/nvfs
d6f6b3b Changes for Mac OS X
803fcc3 Initia...
spring scoped proxy bean
...ion as it stands is incomplete):
<bean id="userPreferences" class="com.foo.UserPreferences" scope="session"/>
<bean id="userManager" class="com.foo.UserManager">
<property name="userPreferences" ref="userPreferences"/>
</bean>
From the above configuration it is eviden...
include external .js file in node.js app
...
To place an emphasis on what everyone else has been saying var foo in top level does not create a global variable. If you want a global variable then write global.foo. but we all know globals are evil.
If you are someone who uses globals like that in a node.js project I was on I would r...
MongoDB/NoSQL: Keeping Document Change History
...tle: [
{ version: 1, value: "Hello world" },
{ version: 6, value: "Foo" }
],
body: [
{ version: 1, value: "Is this thing on?" },
{ version: 2, value: "What should I write?" },
{ version: 6, value: "This is the new body" }
],
tags: [
{ version: 1, value: [ "test", "tri...
Detect if an input has text in it using CSS — on a page I am visiting and do not control?
...ty when any character (even a space) is entered.
Example:
<style>
#foo { background: yellow; }
#foo:valid { outline: solid blue 2px; }
#foo:invalid { outline: solid red 2px; }
</style>
<input id=foo required>
The pseudo-classed :valid and :invalid are defined in Working Draft l...
How do I get the number of elements in a list?
...
1. __foo__: this is just a convention, a way for the Python system to use names that won't conflict with user names. 2. _foo: this is just a convention, a way for the programmer to indicate that the variable is private (whatever ...
How to set environment variables in Python?
...) # Check an existing env. variable
True
>>> os.environ.has_key('FOO') # Check for a non existing variable
False
>>> os.environ['FOO'] = '1' # Set a new env. variable (String value)
>>> os.environ.has_key('FOO')
True
>>> os.environ.get('FOO') # Retrie...
Expression Versus Statement
...If I'm not mis-interpreting you here, you seem to claim that "(setf (third foo) 'goose)" is an expression, not a statement, both because it's Lisp, which "doesn't have statements," and because Lisp is more than a decade older than C, which was the "earliest popular language to blur the lines [betwee...
XML parsing of a variable string in JavaScript
...Name() to get the nodes you want.
Example usage:
var xml = parseXml("<foo>Stuff</foo>");
alert(xml.documentElement.nodeName);
If you're using jQuery, from version 1.5 you can use its built-in parseXML() method, which is functionally identical to the function above.
var xml = $.parse...