load_yaml_with_py_eval
full name: tenpy.tools.params.load_yaml_with_py_eval
parent module:
tenpy.tools.params
type: function
- tenpy.tools.params.load_yaml_with_py_eval(filename=None, yaml_content=None, context={'np': <module 'numpy' from '/home/docs/checkouts/readthedocs.org/user_builds/tenpy/envs/v1.0.4/lib/python3.11/site-packages/numpy/__init__.py'>})[source]
Load a yaml file with support for an additional !py_eval tag.
When defining yaml parameter files, it’s sometimes convenient to just have python snippets in there, e.g. to get fractions of pi or expand last lists.
This function loads a yaml file supporting such (short) python snippets that get evaluated by python’s
eval(snippet)
.It expects one string of python code following the
!py_eval
tag. The most reliable method to pass the python code is to use a literal string in yaml, as shown in the example below.a: !py_eval | 2**np.arange(6, 10) b: !py_eval | [10, 15] + list(range(20, 31, 2)) + [35, 40] c: !py_eval "2*np.pi * 0.3"
Note that a subsequent
yaml.dump()
might contain ugly parts if you construct generic python objects, e.g., a numpy array scalar likenp.arange(10)[0]
. If you want to avoid this, you can explicitly convert back to lists before.Warning
Like pickle, it is not safe to load a yaml file from an untrusted source! A malicious file can call any Python function and should thus be treated with extreme caution.
- Parameters:
- Returns:
Data (typically nested dictionary) as defined in the yaml file.
- Return type:
config