tomllib — Parse TOML files — Python 3.14.6 documentation
Description: Source code: Lib/tomllib This module provides an interface for parsing TOML 1.0.0 (Tom’s Obvious Minimal Language, https://toml.io). This module does not support writing TOML. This module defines t...

# `tomllib` — Parse TOML files

Added in version 3.11.

Source code: Lib/tomllib

This module provides an interface for parsing TOML 1.0.0 (Tom’s Obvious Minimal Language, https://toml.io). This module does not support writing TOML.

Warning

Be cautious when parsing data from untrusted sources. A malicious TOML string may cause the decoder to consume considerable CPU and memory resources. Limiting the size of data to be parsed is recommended.

See also

The Tomli-W package is a TOML writer that can be used in conjunction with this module, providing a write API familiar to users of the standard library `marshal` and `pickle` modules.

See also

The TOML Kit package is a style-preserving TOML library with both read and write capability. It is a recommended replacement for this module for editing already existing TOML files.

This module defines the following functions:

tomllib.load(fp, /, *, parse_float=float)

  Read a TOML file. The first argument should be a readable and binary file object. Return a `dict`. Convert TOML types to Python using this conversion table.

  parse_float will be called with the string of every TOML float to be decoded. By default, this is equivalent to `float(num_str)`. This can be used to use another datatype or parser for TOML floats (e.g. `decimal.Decimal`). The callable must not return a `dict` or a `list`, else a `ValueError` is raised.

  A `TOMLDecodeError` will be raised on an invalid TOML document.

tomllib.loads(s, /, *, parse_float=float)

  Load TOML from a `str` object. Return a `dict`. Convert TOML types to Python using this conversion table. The parse_float argument has the same meaning as in `load()`.

  A `TOMLDecodeError` will be raised on an invalid TOML document.

The following exceptions are available:

exception tomllib.TOMLDecodeError(msg, doc, pos)

  Subclass of `ValueError` with the following additional attributes:

  msg

    The unformatted error message.

  doc

    The TOML document being parsed.

  pos

    The index of doc where parsing failed.

  lineno

    The line corresponding to pos.

  colno

    The column corresponding to pos.

  Changed in version 3.14: Added the msg, doc and pos parameters. Added the `msg`, `doc`, `pos`, `lineno` and `colno` attributes.

  Deprecated since version 3.14: Passing free-form positional arguments is deprecated.

## Examples

Parsing a TOML file:

    import tomllib

    with open("pyproject.toml", "rb") as f:
        data = tomllib.load(f)

Parsing a TOML string:

    import tomllib

    toml_str = """
    python-version = "3.11.0"
    python-implementation = "CPython"
    """

    data = tomllib.loads(toml_str)

## Conversion Table

TOML | Python
--- | ---
TOML document | dict
string | str
integer | int
float | float (configurable with parse_float)
boolean | bool
offset date-time | datetime.datetime (`tzinfo` attribute set to an instance of `datetime.timezone`)
local date-time | datetime.datetime (`tzinfo` attribute set to `None`)
local date | datetime.date
local time | datetime.time
array | list
table | dict
inline table | dict
array of tables | list of dicts