大约有 19,000 项符合查询结果（耗时：0.0215秒） [XML]
How do you delete a column by name in data.table?
To get rid of a column named "foo" in a data.frame , I can do:
8 Answers
8
...
Regular Expression for alphanumeric and underscores
I would like to have a regular expression that checks if a string contains only upper and lowercase letters, numbers, and underscores.
...
What Computer Science concepts should I know? [closed]
What concepts in Computer Science do you think have made you a better programmer?
33 Answers
...
Getting the closest string match
I need a way to compare multiple strings to a test string and return the string that closely resembles it:
12 Answers
...
Is there a Unix utility to prepend timestamps to stdin?
I ended up writing a quick little script for this in Python, but I was wondering if there was a utility you could feed text into which would prepend each line with some text -- in my specific case, a timestamp. Ideally, the use would be something like:
...
Difference between add(), replace(), and addToBackStack()
What is the main difference between calling these methods:
9 Answers
9
...
How do I add a ToolTip to a control?
I have some controls that I would like to display a ToolTip for when the mouse is hovering over it. How can I do this? I would like to know how to do this properly in code, but also in the designer (There is a ToolTip component in the toolbox, but I don't quite.. get it).
...
Network tools that simulate slow network connection [closed]
I would like to visually evaluate web pages response time for several Internet connections types (DSL, Cable, T1, dial-up etc.) while my browser and web server are on the same LAN or even on the same machine. Are there any simple network tools or browser plug-ins that slow down network bandwidth to ...
Calling constructors in c++ without new
I've often seen that people create objects in C++ using
7 Answers
7
...
How to document class attributes in Python? [closed]
I'm writing a lightweight class whose attributes are intended to be publicly accessible, and only sometimes overridden in specific instantiations. There's no provision in the Python language for creating docstrings for class attributes, or any sort of attributes, for that matter. What is the expec...