为什么我不能关闭泡菜文件？

Question

I have been working on a classifier model, using GridSearchCV to find the best hyperparameters. I then pickled the model, and loaded it back (to save time everytime I have to run the notebook).

When I try to close it though, I get this error:

AttributeError: 'GridSearchCV' object has no attribute 'close'

This is my code:

# Save the Grid Search CV object as a pickle file
pickle.dump(knn_grid, open(r'./knn_grid_model.p', 'wb'))
# load the Grid Search CV object
knn_grid = pickle.load(open(r'./knn_grid_model.p', 'rb'))
# Close the file
knn_grid.close()

Any idea on how to overcome this? Will it be a big deal if I don't close the pickle file?

Answer 1

knn_grid isn't a file, it's the GridSearchCV object that was unpickled.

However, your second question still stands:

Will it be a big deal if I don't close the pickle file?

The way your code is written, the file may be left open until being garbage-collected or until the Python interpreter exits. Now, leaving a file open for reading shouldn't cause any problems, but leaving a file open for writing could cause missing data . So the best practice is to use a with statement to ensure that the content is written and the file is closed:

with open('./knn_grid_model.p', 'wb') as f:
    pickle.dump(knn_grid, f)

with open('./knn_grid_model.p', 'rb') as f:
    knn_grid = pickle.load(f)

(Note that the r-strings don't make any difference in this case.)