qs-codec

A query string encoding and decoding library for Python.

Ported from qs for JavaScript.

Highlights

• Nested dictionaries & lists: foo[bar][baz]=qux ⇄ {'foo': {'bar': {'baz': 'qux'}}}.

• Multiple list formats: INDICES (a[0]=x), BRACKETS (a[]=x), REPEAT (a=x&a=y), COMMA (a=x,y) with optional comma round-trip.

• Dot-notation: parse/encode keys like a.b=c as nested; option to encode dots in keys when using dot notation.

• Charset handling: UTF-8 (default) and Latin-1; optional charset sentinel (utf8=✓) to auto-detect encoding.

• Pluggable hooks: custom encoder/decoder callables; options to sort keys, filter output, and control percent-encoding (keys-only, values-only).

• Nulls & empties: strict_null_handling and skip_nulls; support for empty lists/arrays when desired.

• Dates: serialize_date for ISO 8601 or custom (e.g., UNIX timestamp).

• Safety limits: configurable nesting depth, parameter limit, and list index limit; optional strict-depth errors; duplicate-key strategies (combine/first/last).

• Extras: numeric entity decoding (e.g. ☺ → ☺), alternate delimiters/regex, and query-prefix helpers.

Usage

A simple usage example:

import qs_codec as qs

# Encoding
assert qs.encode({'a': 'b'}) == 'a=b'

# Decoding
assert qs.decode('a=b') == {'a': 'b'}

Contents:

• Decoding
  • dictionaries
  • lists
  • primitive values (int, bool, None, etc.)
• Encoding
• Handling None values
• Dealing with special character sets
• RFC 3986 and RFC 1738 space encoding
• qs_codec
  • qs_codec package

Indices and tables

• Index

• Module Index

• Search Page

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Other ports

Port	Repository	Package
Dart	techouse/qs
Kotlin / JVM + Android AAR	techouse/qs-kotlin
Swift / Objective-C	techouse/qs-swift
.NET / C#	techouse/qs-net
Node.js (original)	ljharb/qs

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Special thanks to the authors of qs for JavaScript: - Jordan Harband - TJ Holowaychuk