fix(unit_type): Fix python-2.7 type-hint error

README.md

@@ -1,44 +1,72 @@
 # PH-Units:
+
 A package for converting common Passive House unit types (IP | SI).
 
 ## Usage:
+
 The most basic usage is a simple conversion from one known unit to another:
+
 ```python
 >>> from ph_units.converter import convert
 >>> # Convert 12.45 meters to feet...
 >>> convert(12.45, "M", "FT") -> 40.85 # FT
 ```
 
-
 The package also has a parser which can take simple text in the format: `"{value} {unit}"` and will split apart the text into a numeric part and a unit part:
+
 ```python
 >>> from ph_units.parser import parse_input
 >>> val, unit = parse_input("0.17 BTU/HR-FT2-F")
 >>> val  # 0.17
 >>> unit # 'BTU/HR-FT2-F'
 ```
+
 The results of the parser can then be fed into the converter
+
 ```
 >>> from ph_units.converter import convert
 >>> convert(val, "W/MK", unit) -> 0.098 # BTU/HR-FT2-F
 ```
 
-- - -
 ## Unit Types Supported:
-* Length (m, cm, mm, in, ft)
-* Area (m2, ft2)
-* volume (m2, ft3, liters, gallons)
-* energy (Wh/M3, Wh/M2, kW/M2, kBtu/ft2, Btu/ft2)
-* power (kW, W, W/M2, W/ft2, W/cfm, Btu/h-ft2, Btu/h)
-* speed (m/d, m/s, m/h, ft/s, ft/d)
-* temperature (C, F)
-* volume flow (m3/hr, cfm)
-
- - - -
- ## Adding New Units:
- The conversion factors used are stored as types in the [`ph_units.unit_types`](https://github.com/PH-Tools/PH_units/tree/main/ph_units/unit_types) directory. Note that the types also allow for common 'alias' descriptions ie: 'feet' can be denoted as "FT", "ft." or even the symbol '
-
-- - - 
-![Tests](https://github.com/PH-Tools/PHX/actions/workflows/ci.yaml/badge.svg )
+
+- area (M2, FT2)
+- density (KG/M3, LB/FT3)
+- emissions factors (G/KWH)
+- energy (Wh/M3, Wh/M2, kW/M2, kBtu/ft2, Btu/ft2)
+- envelope (U-Value, R-Value)
+- length (M, CM, MM, IN, FT)
+- moisture vapor resistance (MNS/G, PERM-IN)
+- power (kW, W, W/M2, W/ft2, W/cfm, Btu/h-ft2, Btu/h)
+- speed (m/d, m/s, m/h, ft/s, ft/d)
+- temperature (C, F)
+- volume flow (M3/HR, CFM)
+- volume (M2, FT3, LITER, GALLON)
+
+## Adding New Units:
+
+The conversion factors used are stored as types in the [`ph_units.unit_types`](https://github.com/PH-Tools/PH_units/tree/main/ph_units/unit_types) directory. Note that the types also allow for common 'alias' descriptions ie: 'feet' can be denoted as "FT", "ft." or even the symbol '
+
+## The `Unit` Type:
+
+The package also includes a new [`Unit`](https://github.com/PH-Tools/PH_units/blob/2d8a1fa6ed368b2410563a226f8ac180e103fcf9/ph_units/unit_type.py#L25) type which subclasses from `float` but also retains the unit-type information. This allows for easy conversion between units. For example:
+
+```python
+>>> from ph_units.unit_type import Unit
+>>> a_meter_value = Unit(1.0, "M")
+>>> print(a_meter_value)
+>>> "1.0 (M)"
+>>> a_foot_value = a_meter_value.as_a("FT")
+>>> print(a_foot_value)
+>>> "3.281(FT)"
+```
+
+This `Unit` type supports basic mathematical operations like addition and subtraction, as well as unit-related operations like 'inversion'.
+
+The `Unit` type also supports serialization and deserialization to and from JSON. Additionally, the `Unit` type can be used as a `dataclass` field type and should serialize properly when dataclass `as_dict` is called on the parent object.
+
+---
+
+![Tests](https://github.com/PH-Tools/PHX/actions/workflows/ci.yaml/badge.svg)
 ![versions](https://img.shields.io/pypi/pyversions/pybadges.svg)
 [![IronPython](https://img.shields.io/badge/ironpython-2.7-red.svg)](https://github.com/IronLanguages/ironpython2/releases/tag/ipy-2.7.8/)

ph_units/unit_type.py

@@ -12,12 +12,12 @@
     # If we can, lets try and play well with dataclasses
     from dataclasses import _FIELD, Field # type: ignore
 except ImportError:
-    # If we are in Python 2.7 (Fuck you Rhino) then fake it
+    # If we are in Python 2.7 (Fuck you Rhino 7) then fake it
     _FIELD = None
 
     class Field(object):
         """Field Protocol for Unit class so it can approximate a dataclass."""
-        def __init__(self, *args, **kwargs) -> None:
+        def __init__(self, *args, **kwargs):
             pass
 
 from ph_units.converter import convert
@@ -240,3 +240,6 @@ def __repr__(self):
     def __str__(self):
         # type: () -> str
         return "{:,.3f} ({})".format(self.value, self.unit)
+
+    def ToString(self):
+        return str(self)