Add write_input to api.py module

iodata/api.py

@@ -30,7 +30,7 @@
 from .utils import LineIterator
 
 
-__all__ = ['load_one', 'load_many', 'dump_one', 'dump_many']
+__all__ = ['load_one', 'load_many', 'dump_one', 'dump_many', 'write_input']
 
 
 def _find_format_modules():
@@ -78,6 +78,43 @@ def _select_format_module(filename: str, attrname: str, fmt: str = None) -> Modu
  attrname, filename))
 
 
+def _find_input_modules():
+ """Return all input modules found with importlib."""
+ result = {}
+ for module_info in iter_modules(import_module('iodata.inputs').__path__):
+ if not module_info.ispkg:
+ format_module = import_module('iodata.inputs.' + module_info.name)
+ result[module_info.name] = format_module
+ return result
+
+
+INPUT_MODULES = _find_input_modules()
+
+
+def _select_input_module(attrname: str, fmt: str) -> ModuleType:
+ """Find an input module with the requested attribute name.
+
+ Parameters
+ ----------
+ attrname
+ The required attribute of the input module.
+ fmt
+ The name of the input module to use.
+
+ Returns
+ -------
+ format_module
+ The module implementing the required input format.
+
+ """
+ if fmt in INPUT_MODULES:
+ if not hasattr(INPUT_MODULES[fmt], attrname):
+ raise ValueError(f'{fmt} input module does not have {attrname}!')
+ return INPUT_MODULES[fmt]
+ else:
+ raise ValueError(f"Could not find input format {fmt}!")
+
+
 def load_one(filename: str, fmt: str = None, **kwargs) -> IOData:
  """Load data from a file.
 
@@ -188,3 +225,25 @@ def dump_many(iodatas: Iterator[IOData], filename: str, fmt: str = None, **kwarg
  format_module = _select_format_module(filename, 'dump_many', fmt)
  with open(filename, 'w') as f:
  format_module.dump_many(f, iodatas, **kwargs)
+
+
+def write_input(iodata: IOData, filename: str, fmt: str, template: str = None, **kwargs):
+ """Write input file using an instance of IOData for the specified software format.
+
+ Parameters
+ ----------
+ iodatas
+ An IOData instance containing the information needed to write input.
+ filename : str
+ The input file name.
+ fmt : str
+ The name of the software for which input file is generated.
+ template : str, optional
+ The template input file.
+ **kwargs
+ Keyword arguments are passed on to the input-specific write_input function.
+ """
+
+ input_module = _select_input_module('write_input', fmt)
+ with open(filename, 'w') as f:
+ input_module.write_input(f, iodata, template=template, **kwargs)