python - How to Copy from IPython session without terminal prompts

Question

Frequently, my workflow involves data cleaning/munging in an IPython shell. This has become particularly wonderful since IPython version 5.0 with all the great upgrades to the terminal interface. So, let's say I make an attempt at sprucing up some piece of unstructured data:

In [11]: for i, (num, header, txt) in enumerate(data):
    ...:     header = [e.strip() for e in header.strip().split('
')]
    ...:     header[4] = header[4].strip(',').split(',')
    ...:     data[i] = (num, header, txt)
    ...:

Fantastic, it works! But now, I would really like to add this to a script in my editor. If I copy and paste from my terminal, I capture all the junk on the left. I can clean this up more-or-less easily in an editor, but it would be great if I could copy the code directly to my clipboard from the terminal without touching the mouse and without grabbing the extra stuff either. Is there such a functionality in IPython?

Answer 1

You can use the %history magic to extract the interesting parts from your session. They will be shown in terminal without any of the junk.

Example

In [1]: import numpy as np    
In [2]: a = np.random(10)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-2-83ce219ad17b> in <module>()
----> 1 a = np.random(10)

TypeError: 'module' object is not callable

In [3]: a = np.random.random(10)
In [4]: for i in a:
   ...:     print(i)
   ...:     
0.688626523886
[...]
0.341394850998

If I want to save a part of the session above I can use:

In [5]: %history 1 3-4

import numpy as np
a = np.random.random(10)
for i in a:
    print(i)

In the example above I used %history 1 3-4 to assemble all the commands I want to keep and omit the ones I do not need (Line 2, the one with the error). Now you have version of your session that can be nicely copied.

Writing a file

You can also directly write this to file using the -f FILENAME as parameter.

In [8]: %history 1 3-4 -f /tmp/foo.py

Be careful though, this will overwrite existing files. More Details can be found in the documentation of the %history magic.