QST: Appending to pandas DataFrames
Like a lot of people, I wrote some code that attempted to call `DataFrame.append()` a few million times, and it was slow. So I read the pandas docs ("don't do that, use `pd.concat()`") and StackOverflow (blah blah blah Ginger) and decided that if I was going to write a function that made chunks of dataframe and then concatenated them, the least I could do would be to make it general purpose, and a package others could use.

Thus I created [pandas-appender](https://github.com/wumpus/pandas-appender).

It has some features that I care about -- scalability to 100s of millions of rows, and features that help specify or identify categorical columns. But of course, it's not quite compatible with `DataFrame.append()`, and I'm new enough to pandas to be unsure if I've made it follow pandas conventions as far as possible.

So my question is, can someone who is better versed in pandas conventions than I am, preferably someone who would love to use a package that let them easily build up a dataframe with `.append()`, take a look at this code and give me some advice?

Thanks in advance!
