[FIXED] ipython/python console with my own parser/processor?

Issue

Is there an easy way to make ipython console redirect the cmd-line towards external parser and then output the result in the current session.

Say for example I have parser that calculates expressions (just for the sake of the example). Then I want when the cmd-line starts with "calc:" to pass it to this external parser ... here is hypothetical example :

In[XX]: calc: 5 + 5
  external calc: 5 + 5 = 10

and so on, you get the idea..

---

this is the closest I found so far : first create a shell script :

 #!/bin/sh
 echo $1

then in ipython :

 In [473]: !./x 123
 123

if it is in system path then even shorter :

 In [475]: !x 123
 123

Now if I can share state across invocations.

Solution

I made it work as extension :

from __future__ import print_function
from IPython.core.magic import (Magics, magics_class, line_magic, cell_magic, line_cell_magic)
from bi_lang import *

@magics_class
class BiMagics(Magics):

    def __init__(self, shell):
        super(BiMagics, self).__init__(shell)
        self.bi = BiLang()

    @line_magic
    def do(self, line):
        rv = self.bi.run(line)
        return rv

ip = get_ipython()
magics = BiMagics(ip)
ip.register_magics(magics)

Then :

 In [3]: %reload_ext ipython_extension
 In [4]: %do 5 + 6 
 ===== return ast =====
 Value
 +- val 11
 `- vtype 'num'

If you need more info, look here : http://ipython.readthedocs.io/en/stable/config/custommagics.html#defining-magics

Answered By - sten