Appending data to a json file
dieter at handshake.de
Tue Apr 4 01:31:30 EDT 2017
Dave <dboland9 at fastmail.fm> writes:
> I created a python program that gets data from a user, stores the data
> as a dictionary in a list of dictionaries. When the program quits, it
> saves the data file. My desire is to append the new data to the
> existing data file as is done with purely text files.
Usually, you cannot do that:
JSON representations is not a valid JSON representation.
Thus, you cannot expect that after such a concatenation, a single
call to "load" will give you back complete information (it might
be that a sequence of "load"s works).
Personally, I would avoid concatenated JSON representations.
Instead, I would read in (i.e. "load") the existing data,
construct a Python object from the old and the new data (likely in the form
of a list) and then write it out (i.e. "dump") again.
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