Java abstract class and interface

Java abstract class and interface and their difference.

Extract the i-th digit of integers

Extract the i-th digit of any integers, where i starts from right to left.

HTML div and span

Introduction to html div and span elements and their differences.

Python encoding and unicode

Python source code encoding and unicode in 2.x.

CSS placement

Three kinds of css placement in HTML.

Python main

What the if __name__ == '__main__'does in python and practice of defining python main functions.

Python function arguments

Python function standard arguments, positional arguments, and keyword arguments.

Selenium xpath selector

Selenium web element locating strategy using xpath.

Python aop with decorators

Python AOP (aspect oriented programming) with decorators.

Selenium css selector

Selenium web element locating strategy using css selector.