tomllib --- 剖析 TOML 檔案

原始碼：Lib/tomllib

---

This module provides an interface for parsing TOML 1.1.0 (Tom's Obvious Minimal Language, https://toml.io). This module does not support writing TOML.

在 3.11 版被加入: The module was added with support for TOML 1.0.0.

在 3.15 版的變更: Added TOML 1.1.0 support. See the What's New for details.

警告

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.

也參考

Tomli-W 套件是一個 TOML 編寫器，可以與此模組結合使用，以提供標準函式庫中 marshal 和 pickle 模組之使用者所熟悉的寫入 API。

也參考

TOML 工具套件是一個保留風格且具有讀寫能力的 TOML 函式庫。若要編輯已存在的 TOML 文件，建議用它來替換此模組。

此模組定義了以下函式：

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

讀取一個 TOML 檔案。第一個引數應為一個可讀取的二進位檔案物件。回傳一個 dict。用這個轉換表將 TOML 型別轉換成 Python 的。

parse_float 會被呼叫於要解碼的每個 TOML 浮點數字串。預設情況下，這相當於 float(num_str)。若有使用另一種資料型別或剖析器的 TOML 浮點數（例如 decimal.Decimal），這就派得上用場。可呼叫物件不得回傳 dict 或 list，否則會引發 ValueError。

不合格的 TOML 文件會使得 TOMLDecodeError 被引發。

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

自一個 str 物件載入成 TOML。回傳一個 dict。用這個轉換表轉換 TOML 型別成 Python 的。parse_float 引數和 load() 中的相同。

不合格的 TOML 文件會使得 TOMLDecodeError 被引發。

以下為可用的例外：

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.

在 3.14 版的變更: Added the msg, doc and pos parameters. Added the msg, doc, pos, lineno and colno attributes.

在 3.14 版之後被棄用: 傳遞自由形式的位置引數已被棄用。

範例

剖析一個 TOML 檔案：

import tomllib

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

剖析一個 TOML 字串：

import tomllib

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

data = tomllib.loads(toml_str)

轉換表

TOML	Python
TOML 文件	dict
string	str
integer	int
float	float（可透過 parse_float 調整）
boolean	bool
偏移日期時間 (offset date-time)	datetime.datetime（設定 tzinfo 屬性為 datetime.timezone 的實例）
本地日期時間 (local date-time)	datetime.datetime（設定 tzinfo 為 None）
本地日期 (local date)	datetime.date
本地時間 (local time)	datetime.time
array	list
table	dict
行內表格 (inline table)	dict
表格陣列 (array of tables)	dict 串列 (list of dicts)

Limits and interoperability considerations

tomllib places some limits on the documents it can handle, and it preserves details that other TOML parsers are allowed to ignore. When writing portable TOML files, only use features that are guaranteed or recommended by the standard.

The implementation details listed here may change in future versions of Python.

Tables/dicts

The TOML spec does not guarantee key/value pairs in TOML documents and tables to be in any specific order.

CPython 實作細節： tomllib loads dictionary entries in the order they appear in the source.

Integers

TOML recommends supporting integers in range(−2**63, 2**63).

CPython 實作細節： tomllib uses Python's limit on integer string conversion (4300 digits by default).

Floats

TOML recommends supporting at least IEEE 754 binary64 values, which means that numbers with more than 15 significant decimal digits are likely to be rounded.

CPython 實作細節： tomllib uses Python float by default; on many common platforms this is the recommended binary64. See sys.float_info for details.

Nesting limit

TOML 1.1.0 does not recommend a limit on how deeply arrays and tables may be nested inside one another. (A limit of 100 has been proposed for a future version of TOML.)

CPython 實作細節： In tomllib, the nesting level is mainly limited by Python's recursion limit. Note that code that calls tomllib may contribute to the limit.