uzon 0.7.2

Parse and generate UZON data format

uzon

A Python parser and generator for the UZON typed data expression format — spec v0.7.

import uzon

data = uzon.loads('''
    server is {
        host is "localhost"
        port is 8080 as u16
        debug is true
    }
''')
print(data["server"]["host"])   # "localhost"
print(data["server"]["port"])   # UzonInt(8080, 'u16')

>>> uzon.__version__
'0.7.2'

Installation

pip install uzon

Requires Python 3.10+. No dependencies.

Quick Start

import uzon

# Parse a UZON string
data = uzon.loads('name is "Alice", age is 30')

# Parse a .uzon file
data = uzon.load("config.uzon")

# Generate UZON text from a dict
text = uzon.dumps({"name": "Alice", "age": 30})

# Write UZON to a file
uzon.dump({"name": "Alice"}, "output.uzon")

# Plain mode — strip all type wrappers
plain = uzon.loads('port is 8080 as u16', plain=True)
assert type(plain["port"]) is int  # plain int, not UzonInt

# Deep merge for config overlays
base = uzon.loads('host is "localhost", port is 8080')
override = uzon.loads('port is 9090, debug is true')
merged = uzon.merge(base, override)
# {"host": "localhost", "port": 9090, "debug": True}

# JSON serialization
import json
data = uzon.loads('color is red from red, green, blue')
json.dumps(data, default=uzon.json_default)

# Create typed values from Python
port = uzon.val.u16(8080)
score = uzon.val.f32(9.5)

UZON Syntax Preview

// Scalars
name is "hello"
count is 42
ratio is 3.14
active is true
missing is null

// Typed numbers
port is 8080 as u16
temperature is -40 as i8
weight is 72.5 as f32

// Structs
server is {
    host is "0.0.0.0"
    port is 443 as u16
}

// Lists
tags are "web", "api", "v2"
matrix is [ [ 1, 2 ], [ 3, 4 ] ]

// Tuples
point is (10, 20)

// Enums
color is red from red, green, blue called RGB

// Unions
value is 42 from union i32, f64, string

// Tagged unions
result is "success" named ok from ok as string, err as string called Result

// Functions
double is function x as i32 returns i32 { x * 2 }

// Standard library
evens is std.filter([ 1, 2, 3, 4 ], function n as i64 returns bool { n % 2 is 0 })
upper is std.upper("hello")

// Expressions
total is price * quantity
greeting is "Hello, " ++ name

// Conditionals
mode is if debug then "verbose" else "quiet"
label is case color
    when red then "Red"
    when green then "Green"
    else "Blue"

// Copy-and-update
dev_server is server with { port is 3000 as u16 }

// Extension
extended is server plus { timeout is 30, tls is true }

// Field extraction
port is of server

// Type check
check is value is type i32

// Type dispatch
label is case type value
    when i32 then "integer"
    when f64 then "float"
    else "other"

// Variant dispatch
report is case named result
    when ok then "success"
    when err then "failure"
    else "unknown"

// Environment variables
host is env.HOST or else "localhost"

// File imports
db is struct "database"

See the full UZON specification for details.

---

API Reference

Core Functions

uzon.loads(text, *, plain=False)

Parse and evaluate a UZON string.

def loads(text: str, *, plain: bool = False) -> dict[str, Any]

Parameters:

Name	Type	Default	Description
text	str	(required)	UZON source text.
plain	bool	False	If True, recursively strip all type wrappers to plain Python equivalents.

Returns: dict[str, Any] — A dict of evaluated bindings. Keys are binding names, values are evaluated UZON values.

Raises:

• UzonSyntaxError — Invalid UZON syntax.
• UzonTypeError — Type annotation or compatibility error.
• UzonRuntimeError — Evaluation error (e.g. undefined in arithmetic, overflow).
• UzonCircularError — Circular dependency between bindings.

Examples:

# Basic parsing
data = uzon.loads('x is 10, y is "hello"')
assert data == {"x": 10, "y": "hello"}

# Typed values are preserved
data = uzon.loads('port is 8080 as u16')
assert isinstance(data["port"], uzon.UzonInt)
assert data["port"].type_name == "u16"
assert data["port"] == 8080  # compares as int

# Plain mode strips type wrappers
data = uzon.loads('port is 8080 as u16', plain=True)
assert type(data["port"]) is int

# Expressions are evaluated
data = uzon.loads('a is 10, b is a * 2')
assert data["b"] == 20

---

uzon.dumps(value, *, indent=4)

Generate UZON text from a Python dict.

def dumps(value: dict[str, Any], *, indent: int = 4) -> str

Parameters:

Name	Type	Default	Description
value	dict[str, Any]	(required)	A dict representing a UZON document.
indent	int	4	Number of spaces per indentation level.

Returns: str — UZON source text.

Examples:

text = uzon.dumps({"name": "Alice", "age": 30})
# 'name is "Alice"\nage is 30'

# With typed values
text = uzon.dumps({"port": uzon.val.u16(8080)})
# 'port is 8080 as u16'

# Custom indentation
text = uzon.dumps({"server": {"host": "localhost"}}, indent=2)

---

uzon.load(source, *, plain=False)

Parse and evaluate a UZON file.

def load(source: str | Path, *, plain: bool = False) -> dict[str, Any]

Parameters:

Name	Type	Default	Description
source	str | Path	(required)	Path to a .uzon file.
plain	bool	False	If True, strip all type wrappers.

Returns: dict[str, Any] — A dict of evaluated bindings.

Raises:

• FileNotFoundError — File does not exist.
• UzonSyntaxError — Invalid UZON syntax.
• UzonTypeError — Type annotation or compatibility error.
• UzonRuntimeError — Evaluation error.
• UzonCircularError — Circular dependency or circular import.

Examples:

data = uzon.load("config.uzon")
data = uzon.load(Path("config.uzon"), plain=True)

---

uzon.dump(value, dest, *, indent=4)

Write UZON text to a file.

def dump(value: dict[str, Any], dest: str | Path, *, indent: int = 4) -> None

Parameters:

Name	Type	Default	Description
value	dict[str, Any]	(required)	A dict representing a UZON document.
dest	str | Path	(required)	Path to write to.
indent	int	4	Number of spaces per indentation level.

Returns: None

Examples:

uzon.dump({"name": "Alice"}, "output.uzon")
uzon.dump(data, Path("config.uzon"), indent=2)

---

uzon.merge(base, override)

Deep-merge two UZON structs (dicts), returning a new dict.

def merge(base: dict[str, Any], override: dict[str, Any]) -> dict[str, Any]

Nested dicts are merged recursively. All other values in override replace base. Type metadata (UzonStruct.type_name) is preserved from override if present, otherwise from base.

Parameters:

Name	Type	Default	Description
base	dict[str, Any]	(required)	The base struct.
override	dict[str, Any]	(required)	The override struct. Values here take precedence.

Returns: dict[str, Any] — A new merged dict. Inputs are not mutated.

Raises:

• TypeError — If either argument is not a dict.

Examples:

base = uzon.loads('host is "localhost", port is 8080')
override = uzon.loads('port is 9090, debug is true')
merged = uzon.merge(base, override)
# {"host": "localhost", "port": 9090, "debug": True}

# Nested merge
base = uzon.loads('db is { host is "localhost", port is 5432 }')
override = uzon.loads('db is { port is 3306 }')
merged = uzon.merge(base, override)
# {"db": {"host": "localhost", "port": 3306}}

# UzonStruct type_name is preserved
base = uzon.val.struct({"x": 1}, type_name="Point")
override = {"x": 2}
merged = uzon.merge(base, override)
assert isinstance(merged, uzon.UzonStruct)
assert merged.type_name == "Point"

---

uzon.pretty_format(value, *, indent=2)

Pretty-format a UZON value for debugging. Unlike dumps() which produces valid UZON source, pretty_format() produces a human-readable representation that shows type information.

def pretty_format(value: Any, *, indent: int = 2) -> str

Parameters:

Name	Type	Default	Description
value	Any	(required)	Any UZON value (dict, list, typed value, etc.).
indent	int	2	Number of spaces per indentation level.

Returns: str — Multi-line human-readable representation.

Examples:

data = uzon.loads('''
    server is {
        host is "localhost"
        port is 8080 as u16
    } called Server
''')
print(uzon.pretty_format(data))
# {
#   server:
#     { as Server
#       host: 'localhost'
#       port: 8080 as u16
#     }
# }

---

uzon.json_default(obj)

JSON serialization hook for UZON types. Pass as the default argument to json.dumps().

def json_default(obj: Any) -> Any

Parameters:

Name	Type	Default	Description
obj	Any	(required)	The object that json.dumps could not serialize natively.

Returns: A JSON-serializable Python value.

Type mapping:

UZON Type	JSON Output
UzonInt / UzonFloat	number (handled natively by json)
UzonEnum	string (variant name)
UzonUnion	inner value (recursive)
UzonTaggedUnion	{"_tag": str, "_value": ...}
UzonStruct	object (handled natively — it's a dict)
UzonUndefined	null
UzonFunction	raises TypeError

Raises:

• TypeError — If the object is a UzonFunction or otherwise not serializable.

Examples:

import json

data = uzon.loads('''
    color is red from red, green, blue
    result is "ok" named ok from ok as string, err as string called Result
    port is 8080 as u16
''')

text = json.dumps(data, default=uzon.json_default)
# {"color": "red", "result": {"_tag": "ok", "_value": "ok"}, "port": 8080}

---

Value Factory (uzon.val)

The val object provides factory methods for creating typed UZON values from Python. Integer and float types are resolved dynamically — any bit width supported by the UZON spec works.

Integer Types: val.i{N}(value) / val.u{N}(value)

Create a typed integer. i = signed, u = unsigned. N = bit width.

val.i8(value: int) -> UzonInt      # signed 8-bit:  -128 to 127
val.i16(value: int) -> UzonInt     # signed 16-bit: -32768 to 32767
val.i32(value: int) -> UzonInt     # signed 32-bit
val.i64(value: int) -> UzonInt     # signed 64-bit
val.i128(value: int) -> UzonInt    # signed 128-bit
val.u8(value: int) -> UzonInt      # unsigned 8-bit: 0 to 255
val.u16(value: int) -> UzonInt     # unsigned 16-bit: 0 to 65535
val.u32(value: int) -> UzonInt     # unsigned 32-bit
val.u64(value: int) -> UzonInt     # unsigned 64-bit
val.u128(value: int) -> UzonInt    # unsigned 128-bit
# ... any bit width: val.i256(), val.u1(), etc.

Raises:

• TypeError — If value is not an int (or is a bool).
• OverflowError — If value is outside the range for the type.

Examples:

port = uzon.val.u16(8080)        # UzonInt(8080, 'u16')
big = uzon.val.i128(2**100)      # UzonInt(..., 'i128')
flag = uzon.val.u1(1)            # UzonInt(1, 'u1')

uzon.val.u8(256)                 # OverflowError: 256 out of u8 range [0, 255]
uzon.val.i8(-129)                # OverflowError: -129 out of i8 range [-128, 127]
uzon.val.u16("80")               # TypeError: val.u16() expects int, got str

Float Types: val.f{N}(value)

Create a typed float. Supported widths: 16, 32, 64, 80, 128.

val.f16(value: float | int) -> UzonFloat
val.f32(value: float | int) -> UzonFloat
val.f64(value: float | int) -> UzonFloat
val.f80(value: float | int) -> UzonFloat
val.f128(value: float | int) -> UzonFloat

Raises:

• TypeError — If value is not a number (or is a bool).

Examples:

score = uzon.val.f32(9.5)        # UzonFloat(9.5, 'f32')
ratio = uzon.val.f64(3.14)       # UzonFloat(3.14, 'f64')
half = uzon.val.f16(0.5)         # UzonFloat(0.5, 'f16')
uzon.val.f32(True)               # TypeError: val.f32() expects number, got bool

val.struct(fields, *, type_name=None)

Create a named UZON struct.

def struct(fields: dict[str, Any], *, type_name: str | None = None) -> UzonStruct

Parameters:

Name	Type	Default	Description
fields	dict[str, Any]	(required)	Dict of field names to values.
type_name	str | None	None	Optional named type (e.g. "Server").

Returns: UzonStruct — A dict subclass with type_name metadata.

Examples:

server = uzon.val.struct(
    {"host": "localhost", "port": uzon.val.u16(8080)},
    type_name="Server",
)
assert server.type_name == "Server"
assert server["host"] == "localhost"

val.enum(value, variants, *, type_name=None)

Create a UZON enum value.

def enum(
    value: str,
    variants: list[str],
    *,
    type_name: str | None = None,
) -> UzonEnum

Parameters:

Name	Type	Default	Description
value	str	(required)	The active variant name.
variants	list[str]	(required)	All allowed variant names.
type_name	str | None	None	Optional named type (e.g. "Color").

Raises:

• ValueError — If value is not in variants.

Examples:

color = uzon.val.enum("red", ["red", "green", "blue"], type_name="RGB")
assert color.value == "red"
assert color == "red"  # compares with str

val.union(value, types, *, type_name=None)

Create a UZON untagged union value.

def union(
    value: Any,
    types: list[str],
    *,
    type_name: str | None = None,
) -> UzonUnion

Parameters:

Name	Type	Default	Description
value	Any	(required)	The inner value.
types	list[str]	(required)	List of allowed type names.
type_name	str | None	None	Optional named type.

Examples:

flexible = uzon.val.union(42, ["string", "i32"])
assert flexible.value == 42
assert flexible == 42  # transparent comparison

val.tagged(tag, value, variants, *, type_name=None)

Create a UZON tagged union value.

def tagged(
    tag: str,
    value: Any,
    variants: dict[str, str | None],
    *,
    type_name: str | None = None,
) -> UzonTaggedUnion

Parameters:

Name	Type	Default	Description
tag	str	(required)	The active variant tag.
value	Any	(required)	The inner value.
variants	dict[str, str | None]	(required)	Map of variant names to their payload types (None for no payload).
type_name	str | None	None	Optional named type (e.g. "Result").

Raises:

• ValueError — If tag is not in variants.

Examples:

result = uzon.val.tagged(
    "ok", "done",
    {"ok": "string", "err": "string"},
    type_name="Result",
)
assert result.tag == "ok"
assert result.value == "done"

---

Types

All type wrappers are importable from uzon:

from uzon import (
    UzonInt, UzonFloat, UzonEnum, UzonUnion,
    UzonTaggedUnion, UzonStruct, UzonTypedList,
    UzonFunction, UzonUndefined,
)

UzonInt

class UzonInt(int)

Typed UZON integer preserving width annotation. Subclasses int — usable anywhere a plain int is expected.

Constructor:

UzonInt(value: int, type_name: str, *, adoptable: bool = False)

Attributes:

Name	Type	Description
type_name	str	Width annotation (e.g. "i32", "u16").
adoptable	bool	True if this is an untyped literal that can adopt another integer type.

Methods:

• to_plain() -> int — Return the underlying plain int.

String representations:

• repr(x) -> UzonInt(10, 'i32')
• str(x) -> 10 (plain integer string)

Arithmetic: All arithmetic operators (+, -, *, //, %, **, &, |, ^, <<, >>, unary -/+/abs/~, round) return UzonInt with the same type_name. If the result overflows the type's range, OverflowError is raised.

x = uzon.val.i8(100)
y = x + 20                  # UzonInt(120, 'i8')
z = x + 30                  # OverflowError: Result 130 overflows i8 range [-128, 127]
assert isinstance(x + 1, uzon.UzonInt)
assert (x + 1).type_name == "i8"

# Direct construction (prefer val factory)
n = UzonInt(42, "i32")

---

UzonFloat

class UzonFloat(float)

Typed UZON float preserving width annotation. Subclasses float.

Constructor:

UzonFloat(value: float, type_name: str, *, adoptable: bool = False)

Attributes:

Name	Type	Description
type_name	str	Width annotation (e.g. "f32", "f64").
adoptable	bool	True if this is an untyped literal that can adopt another float type.

Methods:

• to_plain() -> float — Return the underlying plain float.

String representations:

• repr(x) -> UzonFloat(1.5, 'f32')
• str(x) -> 1.5 (plain float string)

Arithmetic: Operators +, -, *, /, //, %, **, unary -/+/abs, round return UzonFloat with the same type_name. Bitwise operators (&, |, ^, <<, >>, ~) are not supported on floats.

x = uzon.val.f32(1.5)
y = x * 2.0                 # UzonFloat(3.0, 'f32')
z = x / 3.0                 # UzonFloat(0.5, 'f32')
assert isinstance(y, uzon.UzonFloat)

---

UzonEnum

class UzonEnum

Enum value — one variant from a defined set.

Constructor:

UzonEnum(value: str, variants: list[str], type_name: str | None = None)

Attributes:

Name	Type	Description
value	str	The active variant name.
variants	list[str]	All allowed variant names.
type_name	str | None	Named type, if declared with called.

Methods:

• to_plain() -> str — Return the variant name as a plain string.

String representations:

• repr(x) -> UzonEnum('red', type=RGB)
• str(x) -> red (variant name)

Equality: Compares equal to other UzonEnum with the same value and type_name, or to a plain str matching value. Hashable.

Pattern matching (Python 3.10+): __match_args__ = ("value",)

data = uzon.loads('color is red from red, green, blue called RGB')
color = data["color"]
assert color == "red"        # compare with str
assert color.value == "red"
assert color.variants == ["red", "green", "blue"]
print(f"Color: {color}")     # "Color: red"

match color:
    case UzonEnum("red"):
        print("got red")

---

UzonUnion

class UzonUnion

Untagged union — a value with one of several possible types.

Constructor:

UzonUnion(value: Any, types: list[str], type_name: str | None = None)

Attributes:

Name	Type	Description
value	Any	The inner value.
types	list[str]	Allowed type names.
type_name	str | None	Named type, if declared with called.

Methods:

• to_plain() -> Any — Return the inner value.

Transparent access: [], len(), iter(), in, and bool() delegate to the inner value.

Equality: Compares inner values — UzonUnion(42) == 42 is True. Hashable (delegates to inner value).

Pattern matching (Python 3.10+): __match_args__ = ("value",)

data = uzon.loads('value is 42 from union i32, f64, string')
v = data["value"]
assert v == 42
assert v.types == ["i32", "f64", "string"]

match v:
    case UzonUnion(int(n)):
        print(f"integer: {n}")

---

UzonTaggedUnion

class UzonTaggedUnion

Tagged union — a value paired with an explicit variant tag.

Constructor:

UzonTaggedUnion(value: Any, tag: str, variants: dict[str, str | None], type_name: str | None = None)

Attributes:

Name	Type	Description
value	Any	The inner value (payload).
tag	str	The active variant tag.
variants	dict[str, str | None]	Map of variant names to payload types.
type_name	str | None	Named type, if declared with called.

Methods:

• to_plain() -> Any — Return the inner value.

String representations:

• repr(x) -> UzonTaggedUnion('ok', tag='ok', type=Result)
• str(x) -> ok (inner value's string)

Transparent access: [], len(), iter(), in delegate to the inner value.

Equality: Compares both tag AND inner value. Hashable.

Pattern matching (Python 3.10+): __match_args__ = ("tag", "value")

data = uzon.loads('''
    result is "ok" named ok from ok as string, err as string called Result
''')
match data["result"]:
    case UzonTaggedUnion(tag="ok", value=v):
        print(f"Success: {v}")
    case UzonTaggedUnion(tag="err", value=e):
        print(f"Error: {e}")

---

UzonStruct

class UzonStruct(dict)

Dict subclass that preserves a named type annotation for round-trip fidelity. Used when a struct has an explicit called TypeName annotation.

Constructor:

UzonStruct(mapping: dict | None = None, type_name: str | None = None)

Attributes:

Name	Type	Description
type_name	str | None	The named type, or None for anonymous structs.

All standard dict operations work — [], .get(), .keys(), .values(), .items(), in, len(), iteration, etc.

data = uzon.loads('''
    server is {
        host is "localhost"
        port is 8080
    } called Server
''')
server = data["server"]
assert isinstance(server, uzon.UzonStruct)
assert server.type_name == "Server"
assert server["host"] == "localhost"

---

UzonTypedList

class UzonTypedList(list)

List subclass that preserves element type annotation for round-trip fidelity. Produced when a list has an explicit as [Type] annotation.

Constructor:

UzonTypedList(elements: list, element_type: str | None = None)

Attributes:

Name	Type	Description
element_type	str | None	Element type annotation (e.g. "i32", "Server").

All standard list operations work. Subclass of list.

data = uzon.loads('scores is [ 95, 87, 72 ] as [i32]')
scores = data["scores"]
assert isinstance(scores, uzon.UzonTypedList)
assert scores.element_type == "i32"
assert scores[0] == 95

---

UzonFunction

class UzonFunction

Function value — a closure capturing its definition scope. Produced when parsing function param as Type returns Type { body } expressions.

Attributes:

Name	Type	Description
params	list[tuple[str, str, Any]]	Parameter list: [(name, type_name, default_or_None), ...].
return_type	str	Return type name.
type_name	str | None	Named type, if declared with called.

Methods:

• signature() -> tuple[tuple[str, ...], str] — Return (param_types, return_type) for structural comparison.

Functions are not directly callable from Python — they are evaluated within UZON expressions.

data = uzon.loads('double is function x as i32 returns i32 { x * 2 }, result is double(21)')
assert isinstance(data["double"], uzon.UzonFunction)
assert data["result"] == 42

Note: UzonFunction and UzonBuiltinFunction are not JSON-serializable — json_default() raises TypeError for them.

---

UzonBuiltinFunction

class UzonBuiltinFunction

Built-in standard library function (e.g. std.len, std.keys). These are provided by the UZON evaluator and are not directly constructible from Python.

Attributes:

Name	Type	Description
name	str	Function name (e.g. "len", "keys").

# UzonBuiltinFunction appears when a binding captures a std function
data = uzon.loads('my_len is std.len')
assert isinstance(data["my_len"], uzon.UzonBuiltinFunction)

---

UzonUndefined

UzonUndefined: _UzonUndefinedType

Singleton sentinel representing UZON's undefined state — the absence of a value. Distinct from None (null in UZON). In UZON, undefined results from accessing unbound names, unset environment variables, or out-of-bounds indices.

• bool(UzonUndefined) is False.
• Safe for identity comparison: value is UzonUndefined.
• Copy-safe: copy() and deepcopy() return the same singleton.

data = uzon.loads('x is missing_name or else 42')
# missing_name evaluates to undefined, or else provides fallback
assert data["x"] == 42

# Undefined bindings are excluded from results
data = uzon.loads('x is missing_name, y is x or else "fallback"')
assert "x" not in data  # undefined bindings are omitted
assert data["y"] == "fallback"

---

Errors

All UZON errors inherit from UzonError and carry source location information.

from uzon import (
    UzonError,          # base class — catch all UZON errors
    UzonSyntaxError, UzonTypeError,
    UzonRuntimeError, UzonCircularError,
)

UzonError

class UzonError(Exception)

Base class for all UZON errors.

Attributes:

Name	Type	Description
line	int | None	Source line number (1-based).
col	int | None	Source column number (1-based).
file	str | None	Source file path, or None for string input.

Error messages automatically include location info: "File config.uzon, Line 5, col 12: ...".

---

UzonSyntaxError

class UzonSyntaxError(UzonError)

Lexer and parser errors — invalid tokens, unexpected structure, malformed literals.

try:
    uzon.loads('x is {')
except uzon.UzonSyntaxError as e:
    print(e)       # "Line 1, col 7: Expected '}' ..."
    print(e.line)  # 1

---

UzonTypeError

class UzonTypeError(UzonError)

Type annotation and compatibility errors — type mismatches in as, with, plus, branch type mismatch in if/case, or operations between incompatible types.

try:
    uzon.loads('x is "hello" as i32')
except uzon.UzonTypeError as e:
    print(e)  # type mismatch

---

UzonRuntimeError

class UzonRuntimeError(UzonError)

Evaluation errors — division by zero, integer overflow, undefined in arithmetic, string interpolation with undefined, import file not found.

try:
    uzon.loads('x is 1 / 0')
except uzon.UzonRuntimeError as e:
    print(e)  # division by zero

---

UzonCircularError

class UzonCircularError(UzonError)

Circular dependency between bindings, or circular file imports.

try:
    uzon.loads('a is b, b is a')
except uzon.UzonCircularError as e:
    print(e)

---

Plain Mode

When plain=True is passed to loads() or load(), all type wrappers are recursively stripped:

UZON Type	Plain Python Type
UzonInt	int
UzonFloat	float
UzonEnum	str (variant name)
UzonUnion	inner value (unwrapped)
UzonTaggedUnion	inner value (unwrapped)
UzonStruct	dict
bool, str, None	unchanged
list	list (elements recursively stripped)
tuple	tuple (elements recursively stripped)

data = uzon.loads('''
    port is 8080 as u16
    color is red from red, green, blue
    result is "ok" named ok from ok as string, err as string
''', plain=True)

assert type(data["port"]) is int           # not UzonInt
assert type(data["color"]) is str           # not UzonEnum
assert data["result"] == "ok"               # unwrapped from TaggedUnion

---

Links

• UZON Specification
• GitHub Repository

License

MIT