I'm a quantConnect python beginner and having a hard time to find simple to understand examples as well as quantConnect pyton documentation. The quantConnect documentation is a good introduction but it doesn't really have concerete examples.

I've read here I can find some examples: 

Now, I'm looking at this example:

could somebody answer the following questions please:

- what is Field.SevenBar? and where can I find an explanation if I had to find an answer by myself?

- what is lastAction? Where do I learn how to use it?

- what does it mean "data.ContainsKey?

I'm quite concerned in regards of the current available documentation. I'm trying to move from quantopian to QC but it doesn't seem that simple...