<commit_before>[![Build Status](https://github.com/hukkin/tomli/workflows/Tests/badge.svg?branch=master)](https://github.com/hukkin/tomli/actions?query=workflow%3ATests+branch%3Amaster+event%3Apush)
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[![PyPI version](https://img.shields.io/pypi/v/tomli)](https://pypi.org/project/tomli)

# Tomli

> A lil' TOML parser

**Table of Contents**  *generated with [mdformat-toc](https://github.com/hukkin/mdformat-toc)*

<!-- mdformat-toc start --slug=github --maxlevel=6 --minlevel=2 -->

- [Intro](#intro)
- [Installation](#installation)
- [Usage](#usage)
  - [Parse a TOML string](#parse-a-toml-string)
  - [Parse a TOML file](#parse-a-toml-file)
  - [Handle invalid TOML](#handle-invalid-toml)
  - [Construct `decimal.Decimal`s from TOML floats](#construct-decimaldecimals-from-toml-floats)
- [FAQ](#faq)
  - [Why this parser?](#why-this-parser)
  - [Is comment preserving round-trip parsing supported?](#is-comment-preserving-round-trip-parsing-supported)
  - [Is there a `dumps`, `write` or `encode` function?](#is-there-a-dumps-write-or-encode-function)
  - [How do TOML types map into Python types?](#how-do-toml-types-map-into-python-types)
- [Performance](#performance)

<!-- mdformat-toc end -->

## Intro<a name="intro"></a>

Tomli is a Python library for parsing [TOML](https://toml.io).
Tomli is fully compatible with [TOML v1.0.0](https://toml.io/en/v1.0.0).

## Installation<a name="installation"></a>

```bash
pip install tomli
```

## Usage<a name="usage"></a>

### Parse a TOML string<a name="parse-a-toml-string"></a>

```python
import tomli

toml_str = """
           gretzky = 99

           [kurri]
           jari = 17
           """

toml_dict = tomli.loads(toml_str)
assert toml_dict == {"gretzky": 99, "kurri": {"jari": 17}}
```

### Parse a TOML file<a name="parse-a-toml-file"></a>

```python
import tomli

with open("path_to_file/conf.toml", "rb") as f:
    toml_dict = tomli.load(f)
```

The file must be opened in binary mode (with the `"rb"` flag).
Binary mode will enforce decoding the file as UTF-8 with universal newlines disabled,
both of which are required to correctly parse TOML.

### Handle invalid TOML<a name="handle-invalid-toml"></a>

```python
import tomli

try:
    toml_dict = tomli.loads("]] this is invalid TOML [[")
except tomli.TOMLDecodeError:
    print("Yep, definitely not valid.")
```

Note that error messages are considered informational only.
They should not be assumed to stay constant across Tomli versions.

### Construct `decimal.Decimal`s from TOML floats<a name="construct-decimaldecimals-from-toml-floats"></a>

```python
from decimal import Decimal
import tomli

toml_dict = tomli.loads("precision-matters = 0.982492", parse_float=Decimal)
assert toml_dict["precision-matters"] == Decimal("0.982492")
```

Note that `decimal.Decimal` can be replaced with another callable that converts a TOML float from string to a Python type.
The `decimal.Decimal` is, however, a practical choice for use cases where float inaccuracies can not be tolerated.

Illegal types are `dict` and `list`, and their subtypes.
A `ValueError` will be raised if `parse_float` produces illegal types.

## FAQ<a name="faq"></a>

### Why this parser?<a name="why-this-parser"></a>

- it's lil'
- pure Python with zero dependencies
- the fastest pure Python parser [\*](#performance):<commit_msg>Note tomllib in the README (#186)<commit_after>[![Build Status](https://github.com/hukkin/tomli/workflows/Tests/badge.svg?branch=master)](https://github.com/hukkin/tomli/actions?query=workflow%3ATests+branch%3Amaster+event%3Apush)
[![codecov.io](https://codecov.io/gh/hukkin/tomli/branch/master/graph/badge.svg)](https://codecov.io/gh/hukkin/tomli)
[![PyPI version](https://img.shields.io/pypi/v/tomli)](https://pypi.org/project/tomli)

# Tomli

> A lil' TOML parser

**Table of Contents**  *generated with [mdformat-toc](https://github.com/hukkin/mdformat-toc)*

<!-- mdformat-toc start --slug=github --maxlevel=6 --minlevel=2 -->

- [Intro](#intro)
- [Installation](#installation)
- [Usage](#usage)
  - [Parse a TOML string](#parse-a-toml-string)
  - [Parse a TOML file](#parse-a-toml-file)
  - [Handle invalid TOML](#handle-invalid-toml)
  - [Construct `decimal.Decimal`s from TOML floats](#construct-decimaldecimals-from-toml-floats)
  - [Building a `tomli`/`tomllib` compatibility layer](#building-a-tomlitomllib-compatibility-layer)
- [FAQ](#faq)
  - [Why this parser?](#why-this-parser)
  - [Is comment preserving round-trip parsing supported?](#is-comment-preserving-round-trip-parsing-supported)
  - [Is there a `dumps`, `write` or `encode` function?](#is-there-a-dumps-write-or-encode-function)
  - [How do TOML types map into Python types?](#how-do-toml-types-map-into-python-types)
- [Performance](#performance)

<!-- mdformat-toc end -->

## Intro<a name="intro"></a>

Tomli is a Python library for parsing [TOML](https://toml.io).
It is fully compatible with [TOML v1.0.0](https://toml.io/en/v1.0.0).

A version of Tomli, the new `tomllib` module,
will be added to the standard library in Python 3.11
via [PEP 680](https://www.python.org/dev/peps/pep-0680/).
Tomli continues to provide a backport on PyPI for Python versions
where the standard library module is not available
and that have not yet reached their end-of-life.

## Installation<a name="installation"></a>

```bash
pip install tomli
```

## Usage<a name="usage"></a>

### Parse a TOML string<a name="parse-a-toml-string"></a>

```python
import tomli

toml_str = """
           gretzky = 99

           [kurri]
           jari = 17
           """

toml_dict = tomli.loads(toml_str)
assert toml_dict == {"gretzky": 99, "kurri": {"jari": 17}}
```

### Parse a TOML file<a name="parse-a-toml-file"></a>

```python
import tomli

with open("path_to_file/conf.toml", "rb") as f:
    toml_dict = tomli.load(f)
```

The file must be opened in binary mode (with the `"rb"` flag).
Binary mode will enforce decoding the file as UTF-8 with universal newlines disabled,
both of which are required to correctly parse TOML.

### Handle invalid TOML<a name="handle-invalid-toml"></a>

```python
import tomli

try:
    toml_dict = tomli.loads("]] this is invalid TOML [[")
except tomli.TOMLDecodeError:
    print("Yep, definitely not valid.")
```

Note that error messages are considered informational only.
They should not be assumed to stay constant across Tomli versions.

### Construct `decimal.Decimal`s from TOML floats<a name="construct-decimaldecimals-from-toml-floats"></a>

```python
from decimal import Decimal
import tomli

toml_dict = tomli.loads("precision-matters = 0.982492", parse_float=Decimal)
assert toml_dict["precision-matters"] == Decimal("0.982492")
```

Note that `decimal.Decimal` can be replaced with another callable that converts a TOML float from string to a Python type.
The `decimal.Decimal` is, however, a practical choice for use cases where float inaccuracies can not be tolerated.

Illegal types are `dict` and `list`, and their subtypes.
A `ValueError` will be raised if `parse_float` produces illegal types.

### Building a `tomli`/`tomllib` compatibility layer<a name="building-a-tomlitomllib-compatibility-layer"></a>

Python versions 3.11+ ship with a version of Tomli:
the `tomllib` standard library module.
To build code that uses the standard library if available,
but still works seamlessly with Python 3.6+,
do the following.

Instead of a hard Tomli dependency, use the following
[dependency specifier](https://packaging.python.org/en/latest/specifications/dependency-specifiers/)
to only require Tomli when the standard library module is not available:

```
tomli >= 1.1.0 ; python_version < "3.11"
```

Then, in your code, import a TOML parser using the following fallback mechanism:

```python
try:
    import tomllib
except ModuleNotFoundError:
    import tomli as tomllib

tomllib.loads("['This parses fine with Python 3.6+']")
```

## FAQ<a name="faq"></a>

### Why this parser?<a name="why-this-parser"></a>

- it's lil'
- pure Python with zero dependencies
- the fastest pure Python parser [\*](#performance):
{'fraction_non_alphanumeric': 0.1533186382561842, 'fraction_numerical': 0.01151114376683811, 'mean_word_length': 4.459224598930481, 'pattern_counts': {'":': 6, '<': 46, '<?xml version=': 0, '>': 48, 'https://': 20, 'lorem ipsum': 0, 'www.': 1, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '277570', 'n_tokens_mistral': 2914, 'n_tokens_neox': 2753, 'n_words': 753}