Inspector is a re-implementation of Andrew Moffat's Inspect-Shell.

It works with Python 2 and 3.

What it does

Inspector allows you to read, change or add global variables of your Python program from another process (a shell) while your program is running.

You could, for example, add a whole class to your program from the shell and rewrite some function so that it starts using your newly-created class. All that while your program continues to run! Yes, that's pretty cool.

How it works

Inspector has 2 modes; server mode and shell mode. Server mode is run by your Python program (in a separate thread), while the shell mode is run by the inspector itself.

Steps:

1. add import inspector to your program
2. run your program
3. run the inspector with python inspector.py
4. type code into the shell

Inspector also supports tab completion for your program's variables.

After you're done, exit the shell by pressing Ctrl-D or Ctrl-C, or typing exit. You program will continue to run with all the changes made. You can run the inspector again anytime you want.

You can also import the inspector from a Python shell if you just want to see how it works.

Example

Importer's side (your program)

import inspector  # add this line to your program
import time

a = 1
b = 10
limit = 600
update = lambda n: n + 1

while a <= limit:
    if a % b == 0:
        print(a, b)
    a = update(a)
    time.sleep(1)

Inspector's side (the shell)

[user@host dir]$ python inspector.py
<Inspector @ localhost:2971 (importer_file_name.py)>
>>> a
9
>>> a = 100
>>> a
102
>>> b = 1
>>> def update(n):
...     if n % 2 == 0:
...         n = n // 2
...     else:
...         n = n * 3 + 1
...     return n
...
>>> a = 1000 

Advanced options

Inspector allows you to change various settings by adding a variable to your program before importing the inspector:

INSPECTOR_VARIABLE_NAME = 'some value'
import inspector

# and your program here

Possible settings are:

• INSPECTOR_HOST = your-host-name
• INSPECTOR_PORT = port-number
• INSPECTOR_TIMEOUT = seconds
• INSPECTOR_PASSPHRASE = 'anything you want'

If you set these, you'll have to tell the inspector's shell about them, so it can connect properly to your program. You do this by adding command-line arguments, like so:

[user@host dir]$ python inspector.py -l <host> -p <port> -t <timeout> -s <passphrase>

Run python inspector.py --help to get a help message about command-line arguments.

There are two other options that I haven't mentioned yet. These are:

• INSPECTOR_SHELL = True
• INSPECTOR_DISABLE = True

The first one enables shell mode instead of server mode. The second one turns inspector into a normal module, so that you can use parts of it without running the server in the background.

Authors

Andrew Moffat, author of the official (original) implementation and the idea itself
Jure Žiberna, author of this re-implementation