Python types are killing me

I spent probably two hours to get to this point:




All I wanted to do was import a .csv file as a dict type (values accessible by keys) and then be able to selectively choose which ones to do work on.

That didn't make sense, let's see if I can better explain it.

My data is a spreadsheet exported to .csv. Each row is a set of data with different things I need record of, like a date, name, notes, etc. Each column has a title, and DictReader sees this and makes those titles the keys.

So, if my .csv file looks like this

name, age
chris, 29
bob, 42

the dicts look like:

{'name':'chris', 'age':29}
{'name':'bob','age':42}

So the lets say I have a lot of these records and only want to do something with the people that have ages of 29. The above code will do that for me (just replace "print row" with whatever I really want to do).

It took me forever to get to this point because I'm still not used to handling data in Python. I thought that "reader" was a 2d array of dicts, but it's not. I have to by "Pythony" about things.

Dicts, lists, and tuples. I'm having a hard time getting my head around when to use each. Lets say I had a whole lot of data with lots of ages and I wanted to shuttle all the people of a certain age into their own variable for handling. What type is this variable? Is it a list of dicts? Is it something more akin what "reader" is? Is "reader" that csv.DictReader dumped out a list of dicts? The Python console says no - it's an instance of something. If it's not a data type then how am I able to iterate thought it with "for row in reader"?

Every time I jump into Python I wind up coming out with more questions than answers. I have trouble with Python that I never have with C. I will concede that when I do realize how to do something that it's fairly straightforward and only a few lines of code. That's nice. I might need to just surrender the need to know exactly what's going on and hope that this ignorance doesn't cause a massive bug that I can't track down due to not knowing the internals well enough.