大约有 45,000 项符合查询结果（耗时：0.0913秒） [XML]
How can I check if a key exists in a dictionary? [duplicate]
...
if key in array:
# do something
Associative arrays are called dictionaries in Python and you can learn more about them in the stdtypes documentation.
...
When should an IllegalArgumentException be thrown?
... 'recover' from this exception by providing an error message to the user.
If the input originates from your own system, e.g. your database, or some other parts of your application, you should be able to rely on it to be valid (it should have been validated before it got there). In this case it's pe...
Best way to “negate” an instanceof
I was thinking if there exists a better/nicer way to negate an instanceof in Java.
Actually, I'm doing something like:
9 ...
Whether a variable is undefined [duplicate]
How do I find if a variable is undefined?
5 Answers
5
...
Why does Path.Combine not properly concatenate filenames that start with Path.DirectorySeparatorChar
... it's doing exactly what the documentation says.
System.IO.Path.Combine
"If path2 contains an absolute path, this method returns path2."
Here's the actual Combine method from the .NET source. You can see that it calls CombineNoChecks, which then calls IsPathRooted on path2 and returns that path ...
Can I use conditional statements with EJS templates (in JMVC)?
and if yes, what is the syntax?
My goal is to prepend an 's' to the word 'comment' when there is more than one. in an jQuery.ejs template in a JMVC app. The following breaks. I can't find any docs for conditionals...
...
How can I delete a newline if it is the last character in a file?
I have some files that I'd like to delete the last newline if it is the last character in a file. od -c shows me that the command I run does write the file with a trailing new line:
...
Rails: How do I create a default value for attributes in Rails activerecord's model? [duplicate]
...lues
def default_values
self.status ||= 'P' # note self.status = 'P' if self.status.nil? might be safer (per @frontendbeauty)
end
end
share
|
improve this answer
|
f...
Remove empty strings from a list of strings
...
If you're that pressed for performance, itertool's ifilter is even faster—>>> timeit('filter(None, str_list)', 'str_list=["a"]*1000', number=100000) 2.3468542098999023; >>> timeit('itertools.ifilter(None, ...
Where is Python's sys.path initialized from?
...al
location on the filesystem based on what the operating system tells
it. If the OS just says "python" is running, it finds itself in $PATH.
It resolves any symbolic links. Once it has done this, the path of
the executable that it finds is used as the value for sys.executable, no ifs,
ands, or buts...