Python Shelve Module
From the Python 3 documentation
A “shelf” is a persistent, dictionary-like object. The difference with “dbm” databases is that the values (not the keys!) in a shelf can be essentially arbitrary Python objects — anything that the pickle module can handle. This includes most class instances, recursive data types, and objects containing lots of shared sub-objects. The keys are ordinary strings.
>>> import shelve >>> wife = ['Pretty', 'Lovely', 'Nice'] >>> with shelve.open('mydata') as shelf_file: ... shelf_file['wife'] = wife
Open and read variables
>>> with shelve.open('mydata') as shelf_file: ... print(type(shelf_file)) ... print(shelf_file['wife']) ... # <class 'shelve.DbfilenameShelf'> # ['Pretty', 'Lovely', 'Nice']
Just like dictionaries,
shelf values have
values() methods that will return list-like values of the keys and values in the shelf. Since these methods return list-like values instead of true lists, you should pass them to the
list() function to get them in list form.
>>> with shelve.open('mydata') as shelf_file: ... print(list(shelf_file.keys())) ... print(list(shelf_file.values())) ... # ['wife'] # [['Pretty', 'Lovely', 'Nice']]