| py_clear_last_error {reticulate} | R Documentation |
Get or (re)set the last Python error encountered.
py_clear_last_error() py_last_error(exception)
exception |
A python exception object. If provided, the provided exception is set as the last exception. |
For py_last_error(), NULL if no error has yet been encountered.
Otherwise, a named list with entries:
"type": R string, name of the exception class.
"value": R string, formatted exception message.
"traceback": R character vector, the formatted python traceback,
"message": The full formatted raised exception, as it would be printed in
Python. Includes the traceback, type, and value.
And attribute "exception", a 'python.builtin.Exception' object.
The named list has class "py_error", and has a default print method
that is the equivalent of cat(py_last_error()$message).
## Not run:
# run python code that might error,
# without modifying the user-visible python exception
safe_len <- function(x) {
last_err <- py_last_error()
tryCatch({
# this might raise a python exception if x has no `__len__` method.
import_builtins()$len(x)
}, error = function(e) {
# py_last_error() was overwritten, is now "no len method for 'object'"
py_last_error(last_err) # restore previous exception
-1L
})
}
safe_len(py_eval("object"))
## End(Not run)