Cell-var-from-loop warning from Pylint
For the following code:
for sort_key, order in query_data['sort']: results.sort(key=lambda k: get_from_dot_path(k, sort_key), reverse=(order == -1))
Pylint reported an error:
Cell variable sort_key defined in loop (cell-var-from-loop)
Could anyone give a hint what is happening here? From pylint source code the description is:
A variable used in a closure is defined in a loop. This will result in all closures using the same value for the closed-over variable.
But I do not have a clue what it means. Could anyone give an example of the problem?
sort_key in the body of the
lambda will be looked up when the function is actually called, so it will see what ever value
sort_key had most recently. Since you are calling
sort immediately, the value of
sort_key will not change before the resulting function object is used, so you can safely ignore the warning. To silence it, you can make
sort_key the default value of a parameter to the
results.sort(key=lambda k, sk=sort_key: get_from_dot_path(k, sk), reverse=(order == -1))