askerror

Beautiful, contextual Python error explanations — offline, automatic, actionable.

Instead of a raw traceback:

AttributeError: 'NoneType' object has no attribute 'append'

askerror shows:

X AttributeError
'NoneType' object has no attribute 'append'

Location
  File: app.py, line 42
  In: process_data
  Code: items.append("x")

Call Chain
-> main
   app.py:55
 -> process_data
    app.py:42

Suggestion
  * The value became None before calling .append
  * Check if the previous operation returned None
  * Add a guard: if value is not None: value.append(...)

Documentation
  https://docs.python.org/3/library/exceptions.html#attributeerror

---

Features

Feature	Description
Location	Relative file path, line number, function name, and the exact line of code
Call Chain	Visual call chain showing how the error propagated
Smart Suggestions	Rule-based suggestions per error type — no API key needed
Typo Detection	NameError suggests similar variable names using difflib
Environment Checks	Python version, virtual env detection for ModuleNotFoundError
Nearby Files	Lists nearby files when a FileNotFoundError occurs
CLI	askerror run, askerror doctor, askerror report
HTML Reports	Dark-themed HTML error reports with toggleable variable details
Decorator	@explain wraps individual functions
Zero Dependencies	Only rich (for terminal output) and easydotdict (for config)

---

Installation

pip install askerror

Requires Python 3.8+.

---

Usage

Method 1 — Import and Install

import askerror
askerror.install()

Every uncaught exception from that point onward is formatted beautifully.

# examply.py
import askerror
askerror.install()

items = None
items.append("hello")

Run it:

python examply.py

Method 2 — Decorator

from askerror import explain

@explain
def main():
    items = None
    items.append("hello")

main()

Method 3 — CLI

Run any script with beautified errors:

askerror run app.py

askerror run app.py --arg1 value1

---

CLI Commands

askerror run <script> [args...]

Runs a Python script with askerror's exception hook enabled. All arguments after the script name are passed to the script as sys.argv.

askerror run server.py --port 8080

askerror doctor

Checks your Python environment:

• Python version
• Virtual environment status
• rich and easydotdict installation
• Config file status

askerror doctor

askerror report [--output file.html]

Displays the last error report and generates an HTML file with full details:

• Traceback with frames
• Local variables at each frame
• Suggestions
• Documentation links

askerror report --output crash.html

---

Error Types

AttributeError

When items is None and you call items.append(...):

Suggestion
  * The value became None before calling .append
  * Check if the previous operation returned None
  * Add a guard: if value is not None: value.append(...)

NameError

When you mistype a variable name:

Suggestion
  * Did you mean 'username'? Similarity: 88%

TypeError

• len() on a non-sequence → shows what type you gave
• Unsupported operand types → tells you they're incompatible
• Missing/extra function arguments → counts them
• Non-callable object → suggests you check parentheses

KeyError

When accessing a missing dictionary key:

Suggestion
  * Available keys: id, email, created_at
  * 'name' does not exist in the dictionary

IndexError

When accessing an index beyond the list length:

Suggestion
  * List length: 5
  * Valid indexes: 0-4
  * Check that the list has enough elements before accessing

ModuleNotFoundError

When a module is not installed:

Suggestion
  * 'pandas' is not installed.
  * Run: pip install pandas
  * Current Python: 3.12
  * Virtual Environment: Yes

FileNotFoundError

When a file does not exist:

Suggestion
  * Could not find: data.csv
  * Looked in: /home/user/project
  * Nearby files: database.csv, data.json, config.yaml
  * Current Directory: /home/user/project

ValueError

• int("abc") → shows the invalid string
• float("x") → shows the invalid string
• Unpacking mismatches → explains too few / too many values

ZeroDivisionError

When dividing by zero:

Suggestion
  * Division or modulo by zero
  * x became zero here: math.py:88

JSONDecodeError

When parsing invalid JSON:

Suggestion
  * Invalid JSON
  * Line 8
  * Unexpected character — check for trailing commas

SyntaxError

When Python cannot parse your code:

Suggestion
  * Missing ':' — did you forget a colon at the end of the line?
  * Line 5

---

HTML Reports

Generate shareable HTML error reports:

from askerror.html import generate_html_report

report = {
    "type_name": "AttributeError",
    "message": "'NoneType' object has no attribute 'append'",
    "traceback": {"frames": [...]},
    "suggestions": ["..."],
}

html = generate_html_report(report)
with open("error.html", "w") as f:
    f.write(html)

Or from the CLI:

askerror report --output error.html

Each HTML report includes:

• Error type and message
• Suggestions
• Frame-by-frame traceback (click to expand variables)
• Documentation link
• Dark theme (GitHub Dark style)

---

Configuration

Configuration is stored at ~/.askerror/config.json as a dotdict.

from askerror import config

config.ai.provider = "openai"
config.ai.api_key = "sk-..."
config.save()

Key	Default	Description
theme	"auto"	Color theme
ai.enabled	false	Enable AI suggestions
ai.provider	null	AI provider name
ai.model	null	AI model name
output.color	true	Colored terminal output
output.html_reports	true	Enable HTML reports
output.show_variables	true	Show variables in output

---

Architecture

askerror/
├── askerror/
│   ├── __init__.py       # Exports: install(), @explain, config
│   ├── main.py           # Exception hook + @explain decorator
│   ├── config.py         # dotdict-backed persistent config
│   ├── cli.py            # CLI: run, doctor, report
│   ├── html.py           # Dark-themed HTML report generator
│   ├── handlers/
│   │   ├── base.py       # Rich panel renderer + sections
│   │   ├── attribute.py  # NoneType / missing attribute
│   │   ├── type_.py      # TypeError: len, callable, args
│   │   ├── key.py        # KeyError + available keys
│   │   ├── index.py      # IndexError + list length
│   │   ├── name.py       # NameError + difflib suggestions
│   │   ├── module.py     # ModuleNotFoundError + env info
│   │   ├── file.py       # FileNotFoundError + nearby files
│   │   ├── json_error.py # JSONDecodeError + line/col
│   │   ├── value.py      # ValueError: int/float parse
│   │   ├── zero.py       # ZeroDivisionError
│   │   └── syntax.py     # SyntaxError hints
│   └── analyzer/
│       ├── traceback.py  # Frame parser with linecache
│       ├── variables.py  # Local variable extractor
│       ├── history.py    # VariableTracker (optional)
│       └── suggestions.py# Fallback suggestion generator
└── pyproject.toml

---

License

MIT