TOML Kit

0.14.0 verified Tue May 12 auth: no python install: verified quickstart: verified

TOML Kit is a style-preserving TOML library for Python, currently at version 0.14.0. It offers a parser that maintains comments, indentations, whitespace, and internal element ordering, providing an intuitive API for accessing and editing TOML files. The library is actively maintained with regular updates, as seen in its recent releases.

pip install tomlkit

Common errors

error ModuleNotFoundError: No module named 'tomlkit' ↓

cause The 'tomlkit' package is not installed in your Python environment or the environment where you are running your script is not active.

fix

Install the tomlkit library using pip: pip install tomlkit

error AttributeError: module 'tomlkit' has no attribute 'dump' ↓

cause Unlike some other configuration libraries (e.g., json, yaml, built-in toml), tomlkit does not provide a direct `dump()` function to write a TOMLDocument to a file-like object. You need to convert the document to a string first.

fix

Convert the TOMLDocument to a string using tomlkit.dumps() or str() before writing it to a file:

import tomlkit

doc = tomlkit.document()
doc["example"] = "value"

# To write to a file
with open("config.toml", "w") as f:
    f.write(tomlkit.dumps(doc))
# Or using str()
# with open("config.toml", "w") as f:
#     f.write(str(doc))

error KeyError: 'section_name' ↓

cause You are attempting to access or assign a value within a nested TOML table (section) that has not yet been explicitly created in the TOMLDocument.

fix

Ensure that intermediate TOML tables (sections) are created as tomlkit.table() objects before trying to set keys within them:

import tomlkit

doc = tomlkit.document()

# Correct way to create nested sections
doc["server"] = tomlkit.table()
doc["server"]["port"] = 8080

# If you want to add keys to an existing table or create a new one within it
doc["database"] = tomlkit.table()
doc["database"]["connection"] = tomlkit.table()
doc["database"]["connection"]["url"] = "localhost:5432"

Warnings

breaking In version 0.13.0, test failures with Python 3.13.0a4 were fixed, which may affect compatibility with earlier versions of Python 3.13. ↓

fix Upgrade to TOML Kit version 0.13.0 or later.

deprecated The 'loads' function is deprecated in favor of 'parse' for parsing TOML strings. ↓

fix Use 'parse' instead of 'loads' for parsing TOML strings.

gotcha When modifying TOML documents, ensure that changes are made through the provided API to preserve formatting and comments. ↓

fix Use TOML Kit's API methods for modifications to maintain style preservation.

gotcha The test output indicates warnings from pip regarding running as the 'root' user and an available pip update. ↓

fix It is recommended to use a virtual environment for pip operations and consider upgrading pip as suggested in the notice.

Install compatibility verified last tested: 2026-05-12

python os / libc status wheel install import disk

3.10 alpine (musl) - - 0.05s 18.1M

3.10 slim (glibc) - - 0.03s 19M

3.11 alpine (musl) - - 0.09s 20.1M

3.11 slim (glibc) - - 0.07s 21M

3.12 alpine (musl) - - 0.07s 11.9M

3.12 slim (glibc) - - 0.07s 12M

3.13 alpine (musl) - - 0.07s 11.5M

3.13 slim (glibc) - - 0.07s 12M

3.9 alpine (musl) - - 0.04s 17.6M

3.9 slim (glibc) - - 0.04s 18M

Imports

parse
```
from tomlkit import parse
```
Correct import path for the 'parse' function.
dumps
```
from tomlkit import dumps
```
Correct import path for the 'dumps' function.
table
```
from tomlkit import table
```
Correct import path for the 'table' function.

Quickstart verified last tested: 2026-04-23

A quickstart guide demonstrating parsing, modifying, and writing TOML documents using TOML Kit.

from tomlkit import parse, dumps, table

content = """[table]
foo = "bar"  # String
"""
doc = parse(content)
doc['table']['baz'] = 13
tab = table()
tab.add('array', [1, 2, 3])
doc['table2'] = tab
dumps(doc)