ansys.dyna.core.lib.deck.write fails writing keywords without fields

[RaphaelHeiniger]

🔍 Before submitting the issue

• I have searched among the existing issues
• I am using a Python virtual environment

🐞 Description of the bug

There are keywords without fields e.g. *CONTROL_DEBUG. An error is raised when one tries to write a deck containing a keyword without fields. Function def _field_iterator is called even if there are no fields and it requires at least one field.

 45 def _field_iterator(fields: typing.List[Field], long_format: bool) -> typing.Iterable[Field]:

---> 46 assert len(fields) > 0, "at least one field is needed"
47 if fields[0].offset > 0:
48 # insert a blank field in the beginning up to the offset
49 blank_field = Field(name=None, type=None, offset=0, width=fields[0].offset)

AssertionError: at least one field is needed

📝 Steps to reproduce

from ansys.dyna.core.lib.deck import Deck
mydeck = Deck()
mystring = '*CONTROL_DEBUG'
mydeck.loads(mystring)
mydeck.write()

💻 Which operating system are you using?

Windows

📀 Which ANSYS version are you using?

..

🐍 Which Python version are you using?

3.12

📦 Installed packages

ansys-api-dyna==0.4.1
ansys-api-platform-instancemanagement==1.1.0
ansys-dpf-core==0.12.2
-e git+https://github.com/pyansys/pyDyna@11661b7119687e7d762847cff2d3d3643492dcf4#egg=ansys_dyna_core
ansys-platform-instancemanagement==1.1.2
ansys-tools-path==0.7.0
appdirs==1.4.4
asttokens==2.4.1
cachetools==5.5.0
certifi==2024.8.30
charset-normalizer==3.4.0
click==8.1.7
colorama==0.4.6
comm==0.2.2
contourpy==1.3.1
cycler==0.12.1
debugpy==1.8.8
decorator==5.1.1
executing==2.1.0
fonttools==4.54.1
google-api-core==2.23.0
google-api-python-client==2.152.0
google-auth==2.36.0
google-auth-httplib2==0.2.0
googleapis-common-protos==1.66.0
grpcio==1.67.1
hollerith==0.4.1
httplib2==0.22.0
idna==3.10
importlib_metadata==8.5.0
ipykernel==6.29.5
ipython==8.29.0
jedi==0.19.2
jupyter_client==8.6.3
jupyter_core==5.7.2
kiwisolver==1.4.7
matplotlib==3.9.2
matplotlib-inline==0.1.7
nest-asyncio==1.6.0
numpy==2.1.3
packaging==24.2
pandas==2.2.3
parso==0.8.4
pillow==11.0.0
platformdirs==4.3.6
pooch==1.8.2
prompt_toolkit==3.0.48
proto-plus==1.25.0
protobuf==5.28.3
psutil==6.1.0
pure_eval==0.2.3
pyasn1==0.6.1
pyasn1_modules==0.4.1
Pygments==2.18.0
pyparsing==3.2.0
python-dateutil==2.9.0.post0
pytz==2024.2
pyvista==0.44.1
pywin32==308
pyzmq==26.2.0
requests==2.32.3
rsa==4.9
scooby==0.10.0
setuptools==75.5.0
six==1.16.0
stack-data==0.6.3
tornado==6.4.1
tqdm==4.67.0
traitlets==5.14.3
typing_extensions==4.12.2
tzdata==2024.2
uritemplate==4.1.1
urllib3==2.2.3
vtk==9.3.1
wcwidth==0.2.13
zipp==3.21.0