大约有 15,000 项符合查询结果（耗时：0.0308秒） [XML]
“Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP
...uses the same variable name. It is also a major security risk with register_globals turned on. E_NOTICE level error is issued in case of working with uninitialized variables, however not in the case of appending elements to the uninitialized array. isset() language construct can be used to detect if...
What's the difference between a Python “property” and “attribute”?
...ggs)
it looks up eggs in spam, and then examines eggs to see if it has a __get__, __set__, or __delete__ method — if it does, it's a property. If it is a property, instead of just returning the eggs object (as it would for any other attribute) it will call the __get__ method (since we were ...
What is the difference between old style and new style classes in Python?
...o the concept of type:
if x is an instance of an old-style class, then x.__class__
designates the class of x, but type(x) is always <type
'instance'>.
This reflects the fact that all old-style instances, independently of
their class, are implemented with a single built-in type, c...
How to check if the string is empty?
... the fact that empty sequences are false.
So you should use:
if not some_string:
or:
if some_string:
Just to clarify, sequences are evaluated to False or True in a Boolean context if they are empty or not. They are not equal to False or True.
...
Received fatal alert: handshake_failure through SSLHandshakeException
...ificate validation. In most cases, this will be the cacerts file in the JRE_HOME/lib/security directory. If the location of the trust store has been specified using the JVM system property javax.net.ssl.trustStore, then the store in that path is usually the one used by the client library. If you are...
Outputting data from unit test in python
... %r", self.that )
# etc.
self.assertEquals( 3.14, pi )
if __name__ == "__main__":
logging.basicConfig( stream=sys.stderr )
logging.getLogger( "SomeTest.testSomething" ).setLevel( logging.DEBUG )
unittest.main()
That allows us to turn on debugging for specific tests whi...
Adding git branch on the Bash command prompt
...
git 1.9.3 or later: use __git_ps1
Git provides a shell script called git-prompt.sh, which includes a function __git_ps1 that
prints text to add to bash PS1 prompt (includes branch name)
Its most basic usage is:
$ __git_ps1
(master)
It also...
Relationship between SciPy and NumPy
...
Last time I checked it, the scipy __init__ method executes a
from numpy import *
so that the whole numpy namespace is included into scipy when the scipy module is imported.
The log10 behavior you are describing is interesting, because both versions are co...
Is it valid to replace http:// with // in a ?
...wing parts:
foo://example.com:8042/over/there?name=ferret#nose
\_/ \______________/\_________/ \_________/ \__/
| | | | |
scheme authority path query fragment
When defining relative URIs (Section 5.2), you can omit any...
How to go about formatting 1200 to 1.2k in java
...ng, String> suffixes = new TreeMap<> ();
static {
suffixes.put(1_000L, "k");
suffixes.put(1_000_000L, "M");
suffixes.put(1_000_000_000L, "G");
suffixes.put(1_000_000_000_000L, "T");
suffixes.put(1_000_000_000_000_000L, "P");
suffixes.put(1_000_000_000_000_000_000L, "E");
}
publ...