This tour will work a little better in interactive mode, so it'll be better if you get IPython notebook installed and running. You can start it from a terminal by running
First, we need to explain how to run cells. Try to run the cell below!
import pandas as pd print("Hi! This is a cell. Press the ▶ button above to run it")
Hi! This is a cell. Press the ▶ button above to run it
You can also run a cell with Ctrl+Enter or Shift+Enter. Experiment a bit with that.
One of the most useful things about IPython notebook is its tab completion.
Try this: click just after read_csv( in the cell below and press Shift+Tab (or Tab if you're using IPython 1.x) 4 times, slowly
After the first time, you should see this:
After the second time:
After the fourth time, a big help box should pop up at the bottom of the screen, with the full documentation for the
I find this amazingly useful. I think of this as "the more confused I am, the more times I should press Shift+Tab". Nothing bad will happen if you tab complete 12 times.
Okay, let's try tab completion for function names!
You should see this:
Writing code in the notebook is pretty normal.
def print_10_nums(): for i in range(10): print(i, end=',')
As of the latest stable version, the notebook autosaves. You should use the latest stable version. Really.
IPython has all kinds of magic functions. Here's an example of comparing
sum() with a list comprehension to a generator comprehension using the
%time sum([x for x in range(100000)])
CPU times: user 7.93 ms, sys: 2.2 ms, total: 10.1 ms Wall time: 10.2 ms
%time sum(x for x in range(100000))
CPU times: user 8.49 ms, sys: 122 µs, total: 8.62 ms Wall time: 8.61 ms
The magics I use most are
%prun for profiling. You can run
%magic to get a list of all of them, and
%quickref for a reference sheet.
You can also do nutty things like run Perl code in the notebook with cell magics. This is especially cool for things like Cython code, where you can try out Cython really fast with the
%%cython magic (you'll need to install it).
%%perl $_ = "whoa, python!"; s/python/perl/; print
That's it for now!