Configure IPython to use powershell instead of cmd

Question

Searched for this, and couldn\'t seem to find anyone who\'d already asked, so here goes.

I\'m starting to switch over to IPython as my go-to shell on Windows 7, and I\'d

Answer 1

You can use IPython's script magics to execute PowerShell commands.

Define Magics

In your IPython profile, modify ipython_config.py to include the lines:

c.ScriptMagics.script_magics = ['powershell']
c.ScriptMagics.script_paths = {
        'powershell':'powershell.exe -noprofile -command -'}

-command - tells PowerShell to execute the stdin text as the command. You can leave out the -noprofile if you need to load your PS profile, but it will be slower.

You can then use %%powershell as a script cell magic.

In [1]: %%powershell
   ...: 1..5
1
2
3
4
5

Custom Magics

To make it a little easier to use, I defined my own magic function to handle PowerShell commands with both line and cell magics. (see: defining your own magics) This can be loaded automatically by placing the script in your IPython profile's startup folder. (i.e. ~\.ipython\profile_default\startup\05-powershell_magic.py)

from IPython.core.magic import register_line_cell_magic

from IPython import get_ipython
ipython = get_ipython()

@register_line_cell_magic
def ps(line, cell=None):
    "Magic that works both as %ps and as %%ps" 
    if cell is None:
        ipython.run_cell_magic('powershell', '--out posh_output' ,line)
        return posh_output.splitlines()
    else:
        return ipython.run_cell_magic('powershell', line, cell)

Usage Examples

To use the %ps line magic and return the output to a variable:

In [1]: ps_version = %ps $PSVersionTable.PSVersion.ToString()

In [2]: print(ps_version)
['2.0']

To use the %%ps cell magic and output to the console:

In [3]: %%ps
   ...: gci c:\

    Directory: C:\

Mode                LastWriteTime     Length Name
----                -------------     ------ ----
d-r--         10/2/2013  10:39 AM            Program Files
d-r--         12/6/2013   1:44 PM            Program Files (x86)
d----          2/6/2014   4:33 PM            TEMP
d-r--        11/27/2013  11:10 AM            Users
d----         1/13/2014  11:21 AM            Windows

Cell magics can send output to a variable with --out <variable name>:

In [4]: %%ps --out process_name_id
   ...: $procs = gps| select Name, ID
   ...: $procs| ConvertTo-Csv -NoType| select -skip 1

In [5]: import csv

In [6]: list(csv.reader(process_name_id.splitlines()))
Out[6]:
[['7+ Taskbar Numberer', '3400'],
 ['acrotray', '3668'],
 ['armsvc', '1772'],
 ['audiodg', '4160'],
 ['AutoHotkeyU64', '472'],
 ['chrome', '6276'],
 ...

Answer 2

The simplest way is to import os and update environment variable comspec in your Jupiter notebook or python shell

import os
os.environ['comspec']='powershell.exe'
os.getenv('comspec')

Then use following command.

!gc log.txt | select -first 10 # head
!gc -TotalCount 10 log.txt     # also head
!gc log.txt | select -last 10  # tail
!gc -Tail 10 log.txt           # also tail (since PSv3), also much faster than above option
!gc log.txt | more             # or less if you have it installed
!gc log.txt | %{ $_ -replace '\d+', '($0)' }         # sed

and more at https://ss64.com/ps/

Answer 3

It is a little bit dodgy, but you could resort to calling pre-made powershell scripts using

os.system('powershell C:\file.ps1')

or individual commands like so:

os.system("powershell; gci | where {$_.Fullname -contains 'some stuff'}")

EDIT:

I just tested this, and it seems to only have to open a single powershell instance:

os.system("powershell; gci; gc C:\windows\system32\drivers\etc\services; [system.net.dns]::gethostbyaddress('203.20.74.6') | more")

but I guess it could get ugly and slow if you had to call this type of thing many times in a script.