astpretty

3.0.0 · active · verified Mon Apr 13

astpretty is a Python library designed to pretty-print the Abstract Syntax Tree (AST) generated by Python's standard library `ast.parse` function. It offers a more readable, indented, and detailed representation of AST nodes compared to the built-in `ast.dump`, making it useful for debugging and understanding code structure. The current version is 3.0.0, released in May 2022, requiring Python 3.8+. It's a stable, focused utility with infrequent but significant updates.

Warnings

breaking Python 2 support was dropped with `astpretty` version 2.0.0. Version 3.0.0 further increased the minimum Python requirement to 3.8. Older Python 2 or early Python 3 projects will need to use an older `astpretty` version or upgrade their Python interpreter.
Fix: Upgrade your Python environment to 3.8 or newer. For Python 2, use `astpretty < 2.0.0` (not recommended for new development).
gotcha `astpretty.pprint` provides a highly detailed, multi-line, indented output, including `lineno` and `col_offset` by default. This is significantly more verbose than the standard library's `ast.dump`, which outputs a single-line representation. Users accustomed to `ast.dump` might find `astpretty`'s default output overwhelming if they only need a compact string.
Fix: For less verbosity, use `astpretty.pprint(node, show_offsets=False)`. For Python 3.9+, consider `ast.dump(node, indent=...)` if a simpler, indented string is sufficient. `astpretty` generally offers more detailed AST information.
gotcha `astpretty` operates on an existing AST node object, not directly on source code strings. You must first parse your code into an AST object using `ast.parse` from the Python standard library before passing it to `astpretty.pprint` or `astpretty.pformat`.
Fix: Always use `import ast` and `ast.parse(your_code_string)` to obtain an AST node, then pass that node to `astpretty` functions.

Install

pip install astpretty Install latest version

Imports

pprint
```
import astpretty
astpretty.pprint(node)
```
While 'from astpretty import pprint' works, the recommended usage in documentation is 'astpretty.pprint' to avoid name collisions with the standard library's 'pprint' module.

pformat

import astpretty
result = astpretty.pformat(node)

Quickstart

This example demonstrates parsing a simple Python code snippet into an AST using the standard `ast` module and then using `astpretty.pprint` to display its structured, human-readable representation. You can also use `astpretty.pformat` to get the pretty-printed string instead of printing directly to stdout.

import ast
import astpretty

code_snippet = """
def greet(name):
    print(f'Hello, {name}!')
"""

# Parse the code into an AST node
parsed_ast = ast.parse(code_snippet)

# Pretty print the entire AST
astpretty.pprint(parsed_ast)

# Or pretty print a specific node, e.g., the function definition
# astpretty.pprint(parsed_ast.body[0], show_offsets=False, indent='  ') # Example with options

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