More Jupyter: Multiple languages, the console, and caveats

Other languages: R notebooks

Try starting an R notebook, and executing:

require(graphics)
(yl <- range(beaver1$temp, beaver2$temp))

beaver.plot <- function(bdat, ...) {
  nam <- deparse(substitute(bdat))
  with(bdat, {
    # Hours since start of day:
    hours <- time %/% 100 + 24*(day - day[1]) + (time %% 100)/60
    plot (hours, temp, type = "l", ...,
          main = paste(nam, "body temperature"))
    abline(h = 37.5, col = "gray", lty = 2)
    is.act <- activ == 1
    points(hours[is.act], temp[is.act], col = 2, cex = .8)
  })
}
op <- par(mfrow = c(2, 1), mar = c(3, 3, 4, 2), mgp = 0.9 * 2:0)
 beaver.plot(beaver1, ylim = yl)
 beaver.plot(beaver2, ylim = yl)
par(op)

Basically it all works as you’d expect...

More magic inside notebooks

Commands:

ls, cd, !, tab completion
%lsmagic

A list of magics

Import Python code

Generally it’s a bad idea to write a LOT of code in a single cell; we tend to suggest using the notebook as a way to explore data, rather than write lots of code. Luckily, you can import code from modules just like you normally would.

Try entering this in a cell in a Python notebook:

%%file mycode.py
def f():
   print('hello, world')

and then in the following cell, enter:

import mycode
f()

Note, here the ‘%%file’ is just a way of creating a file - you can do that in a variety of ways. Speaking of which...

Console

Basically, you can interact with the file system in a variety of ways: via notebook and/or running code, OR via console/upload/download/edit, OR via terminal.

• upload files;
• download and edit files;
• save and download figures;
• terminal window;

Where is this all running?

The general architecture of Jupyter Notebook is this:

We are running things in mybinder specifically; we’ll cover this later, but: basically we’re running on Google Compute Engine.

Caveats

• long-running notebooks don’t work that well;
• multiple views of the same notebook share the kernel but don’t share the output;
• this is the same on a reload...
• the execution order can be confusing: re-run your notebook from scratch, frequently.

Return to index | Next: ‘make’, a workflow engine

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