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.

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