ast-explore

Tool for exploring the AST of given Python source code.

Installation

This package is available on PyPI. To use it, you can either install with pip:

pip install ast-explore

or use it with uv directly:

uvx ast-explore --help

Usage

At a minimum, you must provide a Python file to analyze:

# previously-installed with pip:
ast-explore source_code.py

# with uv:
uvx ast-explore source_code.py

This will extract all possible data points from every node in the AST generated from that source code and print it to the screen. You may wish to pipe the results to a file or less to process.

Here's a partial example of the output:

📖 Reading Python source code from /.../source_code.py...
🔍 Parsing into a Python 3.14 AST...
✅ Ready to explore the AST! Starting depth-first traversal...

********************************************************************************
**    1. Module (https://docs.python.org/3.14/library/ast.html#ast.Module)    **
********************************************************************************

🌲 Path to this node from the root node of the AST:
   Module

📍 This node type does not have any line number information.

📝 Docstring is missing.

✨ AST node-specific fields and their values:
   - body         : [FunctionDef(n...ype_params=[])]
   - type_ignores : []

********************************************************************************
 2. FunctionDef (https://docs.python.org/3.14/library/ast.html#ast.FunctionDef)
********************************************************************************

🌲 Path to this node from the root node of the AST:
   Module -> FunctionDef

🐍 Source code represented by the node:
   1 | def strip_password(x: dict[str, str]) -> None:
   2 |     try:
   3 |         del x['password']
   4 |     except KeyError:
   5 |         pass

📍 Location in the source code:
   - lineno         : 1
   - end_lineno     : 5
   - col_offset     : 0
   - end_col_offset : 12

📝 Docstring is missing.

✨ AST node-specific fields and their values:
   - name           : 'strip_password'
   - args           : arguments(pos..., defaults=[])
   - body           : [Try(body=[Del... finalbody=[])]
   - decorator_list : []
   - returns        : Constant(value...ne, kind=None)
   - type_comment   : None
   - type_params    : []

********************************************************************************
   3. arguments (https://docs.python.org/3.14/library/ast.html#ast.arguments)
********************************************************************************

🌲 Path to this node from the root node of the AST:
   Module -> FunctionDef -> arguments

📍 This node type does not have any line number information.

✨ AST node-specific fields and their values:
   - posonlyargs : []
   - args        : [arg(arg='x', ..._comment=None)]
   - vararg      : None
   - kwonlyargs  : []
   - kw_defaults : []
   - kwarg       : None
   - defaults    : []

********************************************************************************
**       4. arg (https://docs.python.org/3.14/library/ast.html#ast.arg)       **
********************************************************************************

🌲 Path to this node from the root node of the AST:
   Module -> FunctionDef -> arguments -> arg

🐍 Source code represented by the node:
   1 | def strip_password(x: dict[str, str]) -> None:
     |                    ^^^^^^^^^^^^^^^^^

📍 Location in the source code:
   - lineno         : 1
   - end_lineno     : 1
   - col_offset     : 19
   - end_col_offset : 36

✨ AST node-specific fields and their values:
   - arg          : 'x'
   - annotation   : Subscript(val...), ctx=Load())
   - type_comment : None

Specifying nodes of interest

Use the --types argument to list the nodes you want to explore and only information about those nodes will be shown. Here, we only care about function definition nodes:

# previously-installed with pip:
ast-explore source_code.py --types FunctionDef AsyncFunctionDef

# with uv:
uvx ast-explore source_code.py --types FunctionDef AsyncFunctionDef

Here's an example of the result (there are no async functions in the file analyzed):

📖 Reading Python source code from /.../source-code.py...
🔍 Parsing into a Python 3.14 AST...
✅ Ready to explore the AST! Starting depth-first traversal...

********************************************************************************
 1. FunctionDef (https://docs.python.org/3.14/library/ast.html#ast.FunctionDef)
********************************************************************************

🌲 Path to this node from the root node of the AST:
   Module -> FunctionDef

🐍 Source code represented by the node:
   1 | def strip_password(x: dict[str, str]) -> None:
   2 |     try:
   3 |         del x['password']
   4 |     except KeyError:
   5 |         pass

📍 Location in the source code:
   - lineno         : 1
   - end_lineno     : 5
   - col_offset     : 0
   - end_col_offset : 12

📝 Docstring is missing.

✨ AST node-specific fields and their values:
   - name           : 'strip_password'
   - args           : arguments(pos..., defaults=[])
   - body           : [Try(body=[Del... finalbody=[])]
   - decorator_list : []
   - returns        : Constant(value...ne, kind=None)
   - type_comment   : None
   - type_params    : []

********************************************************************************

🏆 Traversal completed!

Tip

To exclude specific node types instead (for example, if you aren't sure yet, which type you want), use --skip instead of --types.

Interactive mode

Use interactive mode to step through the AST one node at a time:

# previously-installed with pip:
ast-explore source_code.py --interactive

# with uv:
uvx ast-explore source_code.py --interactive

Here's what that looks like:

📖 Reading Python source code from /.../source_code.py...
🔍 Parsing into a Python 3.14 AST...
✅ Ready to explore the AST! Starting depth-first traversal...

********************************************************************************
**    1. Module (https://docs.python.org/3.14/library/ast.html#ast.Module)    **
********************************************************************************

🌲 Path to this node from the root node of the AST:
   Module

📍 This node type does not have any line number information.

❓ Do you want more information on this node? [y]es [n]o [q]uit:

Of course, you can combine --interactive with --types/--skip to customize your exploration. Here, we interactively visit all try blocks:

# previously-installed with pip:
ast-explore source_code.py --interactive --types Try

# with uv:
uvx ast-explore source_code.py --interactive --types Try

Note that the first node we encounter is now the ast.Try node and not the ast.Module node we saw without specifying --types:

📖 Reading Python source code from /.../source_code.py...
🔍 Parsing into a Python 3.14 AST...
✅ Ready to explore the AST! Starting depth-first traversal...

********************************************************************************
**       1. Try (https://docs.python.org/3.14/library/ast.html#ast.Try)       **
********************************************************************************

🌲 Path to this node from the root node of the AST:
   Module -> FunctionDef -> Try

🐍 Source code represented by the node:
   2 |     try:
   3 |         del x['password']
   4 |     except KeyError:
   5 |         pass

❓ Show location fields? [y]es [n]o [q]uit: y

📍 Location in the source code:
   - lineno         : 2
   - end_lineno     : 5
   - col_offset     : 4
   - end_col_offset : 12

❓ Do you want more information on this node? [y]es [n]o [q]uit: y

✨ AST node-specific fields and their values:
   - body      : [Delete(target..., ctx=Del())])]
   - handlers  : [ExceptHandler...body=[Pass()])]
   - orelse    : []
   - finalbody : []

❓ Continue traversal? [y]es [n]o [q]uit:

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ast-explore

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