pysys.utils.safeeval¶
Contains the safeEval
function.
safeEval¶
- pysys.utils.safeeval.safeEval(expr, errorMessage='Failed to evaluate "{expr}" due to {error}', emptyNamespace=False, extraNamespace={})[source]¶
Executes eval(…) on the specified string expression, using a controlled globals()/locals() environment to ensure we do not break compatibility between PySys versions, and that a sensible set of PySys constants and modules are available.
Unless
emptyNamespace=True
, the global environment used for evaluation includes theos.path
,math
,sys
,re
,json
, andlocale
standard Python modules, as well as thepysys
module and the contents of thepysys.constants
module, e.g.IS_WINDOWS
.If necessary, symbols for additional modules can be imported dynamically using
import_module
:x = safeEval("import_module('difflib').get_close_matches('app', ['apple', 'orange', 'applic']")
If an error occurs, an exception is raised that includes the expression in its message.
- Parameters
expr (str) – The string to be evaluated.
errorMessage (str) – The string used for the raised exception message if an exception is thrown by eval, where
{expr}
will be replaced with the actual expression and{error}
with the error message.emptyNamespace (bool) – By default a default namespace is provided including the symbols described above such as
os.path
,pysys
, etc. Set this to True to start with a completely empty namespace with no symbols defined.extraNamespace (dict[str,obj]) – A dict of string names and Python object values to be included in the globals environment used to evaluate this string.
New in version 2.0.