Pandas: Accessing the index of a row in an apply function

September 25, 2017 less than 1 minute read

You CANNOT access each row’s index via lambda x: x.index in DataFrame.apply(axis=1) because apply treats each row as a numpy object, not a Series. However yo...

SemiBoost

September 6, 2017 5 minute read

The inconsistency among the unlabeled examples:

Python GIL: Global Interpreter Lock

September 3, 2017 3 minute read

Python: Put simply, generators are special coroutines

August 31, 2017 12 minute read

next(coro) == coro.send(None)

Python: Yes, coroutines are complicated, but they can be used as simply as generators

August 29, 2017 1 minute read

The fact is that we often take the .send() sematics of coroutines too seriosly that we simply ignore the possibility to use them just like generators.

Python: IDLE won’t display anything for an expression evaluated to None

August 29, 2017 less than 1 minute read

This is trivial but sometimes misleading.

Python: raise / 3 key elements of an exception

August 28, 2017 3 minute read

1. raise-statement in Python 2

Python: except

August 28, 2017 less than 1 minute read

简单说一下。except 可以接一个 tuple 表示捕捉多种类型的异常，也可以不带任何参数表示捕捉 everything（当然这是一个 anti-pattern）。

Python: with-statement / variable scope in with-statement

August 25, 2017 2 minute read

with-statement

Python: try-except-else-finally

August 25, 2017 less than 1 minute read

Python 的 try-except-finally 和 Java 的 try-catch-finally 其实是一样的，烦就烦在中间那个 else 上：