pythermalcomfort 2.8.4 or 2.8.3 --> mutable default <class 'numpy.ndarray'> for field local_bsa is not allowed: use default_factory

[gulermelih]

Hi. This is my first comment. I'm not sure if I'm posting in the right place. I apologize in advance if I'm making a mistake.

When I run below code (or any code with pythermalcomfort)

from pythermalcomfort.models import pmv_ppd

results = pmv_ppd(tdb=22, tr=22, vr=0.1, rh=60, met=1, clo=0.9, standard="ASHRAE")
print(results)

I got the below output;

Traceback (most recent call last):
    from pythermalcomfort.models import pmv_ppd
  File "AppData\Local\Programs\Python\Python311\Lib\site-packages\pythermalcomfort\__init__.py", line 3, in <module>
    from pythermalcomfort.models import *
  File "AppData\Local\Programs\Python\Python311\Lib\site-packages\pythermalcomfort\models.py", line 28, in <module>
    from pythermalcomfort.jos3_functions import thermoregulation as threg
  File "AppData\Local\Programs\Python\Python311\Lib\site-packages\pythermalcomfort\jos3_functions\thermoregulation.py", line 17, in <module>
    from pythermalcomfort.jos3_functions import construction as cons
  File "AppData\Local\Programs\Python\Python311\Lib\site-packages\pythermalcomfort\jos3_functions\construction.py", line 16, in <module>
    from pythermalcomfort.jos3_functions.parameters import Default
  File "AppData\Local\Programs\Python\Python311\Lib\site-packages\pythermalcomfort\jos3_functions\parameters.py", line 20, in <module>
    @dataclass
     ^^^^^^^^^
  File "AppData\Local\Programs\Python\Python311\Lib\dataclasses.py", line 1230, in dataclass
    return wrap(cls)
           ^^^^^^^^^
  File "AppData\Local\Programs\Python\Python311\Lib\dataclasses.py", line 1220, in wrap
    return _process_class(cls, init, repr, eq, order, unsafe_hash,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "AppData\Local\Programs\Python\Python311\Lib\dataclasses.py", line 958, in _process_class
    cls_fields.append(_get_field(cls, name, type, kw_only))
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "AppData\Local\Programs\Python\Python311\Lib\dataclasses.py", line 815, in _get_field
    raise ValueError(f'mutable default {type(f.default)} for field '
ValueError: mutable default <class 'numpy.ndarray'> for field local_bsa is not allowed: use default_factory

When pythermalcomfort version is 2.8.4 or 2.8.3 this error occurs. 2.8.2 and 2.8.1 no issue.

Desktop

• OS: Windows 10 Enterprise 19045.3448
• Visual Studio Code: 1.83.0
• Interpreter: Python 3.11.6 x64

Normally, I was using version pythermalcomfort 2.8.1, but when I looked to check for the latest updates and installed the new version, I encountered this error. The latest version where I do not get any errors is 2.8.2.

Additionally, if you are using Python 3.12.0 version, pythermalcomfort is not installed. This is a different error. I removed python 3.12.0 and install 3.11.6. This is a completely independent and different error from above, I just mentioned it as additional information.

[FedericoTartarini]

Python 3.11 and 3.12 are not yet supported in pythermalcomfort.

Python 3.10

Thank you very much for reporting this issue. I have created a new virtual environment using Python 3.10 and then installed pythermalcomfort with this command:

pip install pythermalcomfort

This installs pythermalcomfort-2.8.4. However, I did not get any error after running the following code:

from pythermalcomfort.models import pmv_ppd
results = pmv_ppd(tdb=22, tr=22, vr=0.1, rh=60, met=1, clo=0.9, standard="ASHRAE")
print(results)

Python 3.12

I created a virtual environment with Python 3.12 and I confirm that I also cannot install pythermalcomfort.

Python 3.11

I created a virtual environment with Python 3.11 and I confirm that I am getting the same error as you.

I, therefore, suggest that you use Python 3.10 while I find a solution to the problem. I hope this works for you and this is not causing too many issues.

[FedericoTartarini]

I believe I was able to fix this issue and in the future pythermalcomfort should be compatible with version 3.11. I am tagging @AkihisaNomoto who wrote the dataclass code.

Aki, I fixed the issue by changing the code as follows:

from typing import ClassVar

import numpy as np

@dataclass(frozen=True)
class Default:
    # Body information
    height: float = 1.72  # [m]
    weight: float = 74.43  # [kg]
    age: int = 20  # [-]
    body_fat: float = 15  # [%]
    cardiac_index: float = 2.59  # [L/min/m2]
    blood_flow_rate: int = 290  # [L/h]
    physical_activity_ratio: float = 1.25  # [-]
    metabolic_rate: float = 1.0  # [met]
    sex: str = "male"
    posture: str = "standing"
    bmr_equation: str = "harris-benedict"
    bsa_equation: str = "dubois"
    local_bsa: ClassVar[list[float]] = np.array(
        [
            0.110,
            0.029,
            0.175,
            0.161,
            0.221,
            0.096,
            0.063,
            0.050,
            0.096,
            0.063,
            0.050,
            0.209,
            0.112,
            0.056,
            0.209,
            0.112,
            0.056,
        ]
    )

    # Environment information
    core_temperature: float = 37  # [°C]
    skin_temperature: float = 34  # [°C]
    other_body_temperature: float = 36  # [°C]
    dry_bulb_air_temperature: float = 28.8  # [°C]
    mean_radiant_temperature: float = 28.8  # [°C]
    relative_humidity: float = 50  # [%]
    air_speed: float = 0.1  # [m/s]
    # Clothing information
    clothing_insulation: float = 0  # [clo]
    clothing_vapor_permeation_efficiency: float = 0.45  # [-]
    lewis_rate = 16.5  # [K/kPa]