Python: Saving dictionary to .py file

Question

I have got a dictionary this_dict produced in a python script that I would like to write to a separate python module dict_file.py. This would allow me to load the dictionary in another script by importing dict_file.

I thought a possible way of doing this was using JSON, so I used the following code:

import json

this_dict = {"Key1": "Value1",
             "Key2": "Value2",
             "Key3": {"Subkey1": "Subvalue1",
                      "Subkey2": "Subvalue2"
                     }
            }

with open("dict_file.py", "w") as dict_file:
    json.dump(this_dict, dict_file, indent=4)

When I opened the resulting file in my editor, I got a nicely printed dictionary. However, the name of the dictionary in the script (this_dict) was not included in the generated dict_file.py (so only the braces and the body of the dictionary were written). How can I include the name of the dictionary too? I want it to generate dict_file.py as follows:

this_dict = {"Key1": Value1,
             "Key2": Value2,
             "Key3": {"Subkey1": Subvalue1,
                      "Subkey2": Subvalue2
                     }
            }

Why don't you use [`pickle`](https://docs.python.org/3.1/library/pickle.html) instead? — roganjosh, Mar 22 '18 at 23:25
Seems easier to just load the file as json `this_dict = json.load(open("dict_file.json"))` instead of generating source code. — ext, Mar 22 '18 at 23:32
2nd the usage of **pickle** https://stackoverflow.com/questions/4530611/saving-and-loading-objects-and-using-pickle — Benedict K., Mar 22 '18 at 23:38

score 3 · Accepted Answer · answered Mar 23 '18 at 00:47

1) use file.write:

file.write('this_dict = ')
json.dump(this_dict, dict_file)

2) use write + json.dumps, which returns a string with json:

file.write('this_dict = ' + json.dumps(this_dict)

3) just print it, or use repr

file.write('this_dict = ')
file.write(repr(this_dict))
# or:
# print(this_dict, file=file)

score 0 · Answer 2 · answered Mar 22 '18 at 23:35

If you don't want to use pickle as @roganjosh proposed in the comments, a hacky workaround would be the following:

this_dict = {"Key1": "Value1",
             "Key2": "Value2",
             "Key3": {"Subkey1": "Subvalue1",
                      "Subkey2": "Subvalue2"
                     }
            }

# print the dictionary instead
print 'this_dict = '.format(this_dict)

And execute the script as:

python myscript.py > dict_file.py

Note: Of course this assumes that you will not have any other print statements on myscript.py.

Python: Saving dictionary to .py file

2 Answers2