Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

How to use pipe in IPython

In a Linux terminal, when the output of one command is too long to read in one page, I can do this:

cat file | less

so that I can read and scroll up and down the output from the cat file.

How can I do this in IPython?

For example, I tried this and it didn't work:

whos | less

My original problem is that the output from whos is too much to be seen by doing Shift+Page Up and I don't want to change the scroll buffer.

like image 483
McBear Holden Avatar asked Apr 21 '11 07:04

McBear Holden


People also ask

How do you break a line with IPython?

If you're having trouble adding newlines in the middle of a multiline code block in IPython, try using Ctrl-V Ctrl-J to insert a linebreak at the cursor.

What is %% Writefile in Jupyter Notebook?

%%writefile lets you output code developed in a Notebook to a Python module. The sys library connects a Python program to the system it is running on. The list sys. argv contains the command-line arguments that a program was run with.

Does Jupyter use IPython?

The IPython kernel is maintained by the Jupyter team, as a result of the evolution of the project. However, you can also run many other languages, such as Scala, JavaScript, Haskell, Ruby, and more in the Jupyter Notebook Application.


2 Answers

In IPython, you can use %page obj to show the object obj using your standard pager (usually less). Alternatively, you can increase the scroll buffer of your terminal, which might be convenient in any case.

%page obj -- display object similar to IPython default display (repr-like), using pager if output size requires

%page -r obj -- display object similar to print, using pager if size requires

%page can only take a plain name or attribute reference. It cannot evaluate an arbitrary expression, but you can use a temporary variable to work around this limitationL

tmp = ex * pr + ess - ion
%page tmp
like image 79
Sven Marnach Avatar answered Oct 03 '22 01:10

Sven Marnach


Use of the pager should be automatic.

From the manual:

In order to configure less as your default pager, do the following:

  1. Set the environment PAGER variable to less.
  2. Set the environment LESS variable to -r (plus any other options you always want to pass to less by default). This tells less to properly interpret control sequences, which is how color information is given to your terminal.

For the bash shell, add to your ~/.bashrc file the lines:

export PAGER=less
export LESS=-r
like image 44
bstpierre Avatar answered Oct 03 '22 00:10

bstpierre