pobshell 0.2.0

A Bash-like shell for Python objects

Pobshell

A Bash‑like shell for live Python objects.

Think cd, ls, cat, and find — but for Python objects instead of files. Stroll around your code, runtime state, and data structures. Inspect everything: modules, classes, live objects. It's pick‑up‑and‑play: familiar commands plus optional new tricks. A fun and genuinely useful way to explore a Python app, package, or Python itself.

https://github.com/user-attachments/assets/d3dc69dd-5195-4b51-81eb-be29637b43a6

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What Is Pobshell For?

• Exploratory debugging – Inspect live object state on the fly
• Understanding APIs – Examine code, docstrings, class trees
• Shell integration – Pipe object state or code snippets to LLMs or OS tools
• Code and data search – Recursive search for object state or source without file paths
• REPL & paused scripts – Explore runtime environments dynamically
• Teaching & demos – Make Python internals visible and walkable

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How It Works

Pobshell maps Python objects to Linux‑style paths:

• Each object is a "directory"
• Each attribute or member is a child in that directory
• Navigate using Bash-style commands

Start Pobshell

import json  # Something to explore

import pobshell
pobshell.shell()

Gives you a prompt with your variables in the root directory

/ ▶ ls
json
/ ▶ cd json
/json ▶ ls
JSONDecodeError  JSONEncoder  decoder          dump   encoder  loads  
JSONDecoder      codecs       detect_encoding  dumps  load     scanner
/json ▶ doc -1
JSONDecodeError  Subclass of ValueError with the following additional properties:
JSONDecoder      Simple JSON <https://json.org> decoder
JSONEncoder      Extensible JSON <https://json.org> encoder for Python data structures.
codecs           codecs -- Python Codec Registry, API and helpers.
decoder          Implementation of JSONDecoder
dump             Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
dumps            Serialize ``obj`` to a JSON formatted ``str``.
encoder          Implementation of JSONEncoder
load             Deserialize ``fp`` (a ``.read()``-supporting file-like object containing
loads            Deserialize ``s`` (a ``str``, ``bytes`` or ``bytearray`` instance
scanner          JSON token scanner

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Core Commands

Pobshell inspection commands are built on Python’s inspect module (mostly).

Command	Description
ls -l	Long listing: names, types, values
ls -x	Extra long listing: ls -l, cat -1, doc -1,...
cat	Show syntax‑highlighted source code
doc	Print docstrings
predicates	Inspect predicates (e.g. isclass)
memsize	Total memory size of object and members
tree	Diagram object structure
find	Recursive search

…more commands

Command	Description
filepath	File where the object was defined
id	Unique identifier of the object
module	Module that defines the object
mro	Method resolution order
abcs	Show abstract base classes
pprint	Pretty-printed object value
pydoc	Auto-generated documentation
repr	saferepr() representation of object value
signature	Function signature
str	str() representation of object value
type	Type of the object
ls	List object members
typename	Name of the object’s type (type.name)
which	Defining class for a method or descriptor

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Command targets

command [TARGET]

• Omit target — inspect all members of the current object. Use -a to include private attributes & dunders.
  E.g. /json/JSONDecodeError ▶ ls -la
• *pattern* — inspect members with matching names.
  E.g. /json ▶ ls -l *Decode*
• /path (no trailing slash) — inspect a specific target object. E.g. / ▶ ls -l /json/JSONDecodeError
• /path/ (trailing slash) — inspect members of target object.
  E.g. / ▶ ls -l /json/JSONDecodeError/

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Filters

Use filters to control which members inspection commands report — filter by type, docstring, source, string representation, Python expression, and more.

N.B. Use same syntax for recursive search with find command.

• Filter by inspect predicate

  • --isfunction, --ismodule, --isclass, etc.
    E.g.
    /path ▶ doc -1 --ismodule
/path ▶ find . --ismodule

• Filter by Pobshell inspection command

  • --doc PATTERN or --cat PATTERN
    E.g.
    /path ▶ cat -n 4 --doc *Encoding*
/path ▶ doc --cat "class\\s+oyster" -ir
/path ▶ find . --cat *TODO* -i

  • --str PATTERN, --mro PATTERN, --abcs PATTERN
    E.g.
    /iris/data ▶ ls -l --str *6.3*

• Filter by Python expression

  • --matchpy PYTHON_EXPR
    E.g.
    /path ▶ find --matchpy "isinstance(self, Cafe)"

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OS Shell Integration

• Pipes and redirection
  E.g. /path ▶ ls -lu | sort -k 2
• Run OS commands with ! — prefix a shell command with !; wrap any Pobshell command in """...""" to execute it first and substitute its output via a temporary file. E.g. /json ▶ !diff """cat dump""" """cat dumps"""
  E.g. /path ▶ !aichat -f """cat ns_path_complete""" Explain how this code works

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Exploring Data Structures

Pobshell lets you remap what you see when you cd into an object. Use the map command to switch modes:

• attributes — show only the object’s attributes (default)
• contents — show only collection items (list, dict, …)
• everything — show attributes and collection items together
• static — read raw __dict__ values, so no descriptor or __getattr__ code is executed

When working with contents, use backticks around any "name" not valid as a Python identifier:

/path ▶ ls /mylist/`0`                    # list index
/path ▶ cd /mydict/`'0'`                  # string key 
/path ▶ predicates /sympy/.../`exp`       # symbolic key
/path ▶ ls -x "/mydict/`foo bar`"         # space in key

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Python expressions

Use Python expressions in filters and commands:

/path ▶ ls -x --matchpy "isinstance(self, Cafe)"
/path ▶ find --typename list --printpy "self[-1]"
/path ▶ printpy "sum(self)" /iris/data
/path ▶ ::import inspect    # add inspect module to root
/path ▶ ::x = 42            # assign x in root

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Features

• Tab completion & history
• Syntax coloring and pagination
• Shortcuts, macros, aliases, scripting
• Supports light and dark themes
• Built in help and man pages full of examples

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Safety & Stability

• Pobshell is in alpha release
• Read‑only by default. Commands such as ls, doc, and cat simply inspect live objects — like pausing in a debugger.
• When can things change? Only if you run Python code (printpy, matchpy, : or ::) or if a property fires.
• Need zero‑side‑effects? Switch to map static to fetch raw __dict__ values without executing descriptors or __getattr__ logic.
• Sandboxing. Adding or removing names under the root path / is local to Pobshell. Edits you make to existing mutable objects (lists, dicts, class attrs) will reflect in your program, just like in a REPL.

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Installation

Pobshell supports Python 3.11 and 3.12. It has minimal dependencies.

$ pip install pobshell

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Platform Compatibility (tested)

Platform	Python	Basic func.	Tab completion	Unit tests
macOS	3.11	Yes	Yes	Yes
macOS	3.12	Yes	Yes	Yes
Linux	3.12	Yes	Yes	Yes
Win 10 WSL	3.13	Yes	Yes	Yes
Win 10 Native	3.12	Yes	Yes	Yes
Win 10 Native	3.13	Yes	No	No

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Quickstart

>>> import pobshell; pobshell.shell()
/ ▶ ls -l

shell() creates a Pobshell virtual filesystem, populates root with globals and locals of the calling frame, and starts a Pobshell command loop. You get a prompt at root for entering Pobshell commands. Use quit to exit.

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Learn more

YouTube demos: https://www.youtube.com/@Pobshell

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Contribute

GitHub: https://github.com/pdalloz/pobshell
Bug reports, feature ideas, and pull requests welcome!

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About the Author

Developed and maintained by Peter Dalloz, data lead and Python engineer.

If you're looking for help with a data or AI project, or any Python codebase, feel free to reach out via LinkedIn. I'm open to permanent onsite roles in the UK (citizen) or Spain (resident), and remote or contract work globally. LinkedIn: https://www.linkedin.com/in/pdalloz