I have a piece of code with the output of dictionaries in a text file, and I had a question whether it can be done with the shelve module?

Question

I have this piece of code

dict3 = {'12345': ['paper', '3'], '67890': ['pen', '78'], '11223': ['olive', '100'], '33344': ['book', 
'18']}

output = open("output.txt", "a", encoding='utf-8')
for k, v in dict3.items():
   output.writelines(f'{k} {v[0]} {v[1]}\n') 
output.close()

When this code is executed I have this result:

12345 paper 3

67890 pen 78

11223 olive 100

33344 book 18

So, maybe someone knows how to do the same, but using the shelve module?

Answer 1

Since shelve shelves smell like dictionaries, you can just use .update() to write that dict into a shelf, then .items() to read:

import shelve

dict3 = {
    '12345': ['paper', '3'],
    '67890': ['pen', '78'],
    '11223': ['olive', '100'],
    '33344': ['book', '18'],
}

with shelve.open("my.shelf") as shelf:
    shelf.update(dict3)

# ...

with shelve.open("my.shelf") as shelf:
    for k, v in shelf.items():
        print(k, v)

Output:

67890 ['pen', '78']
12345 ['paper', '3']
11223 ['olive', '100']
33344 ['book', '18']