0

I have two json files that I'd like to open to read from and instead of calling the open() function twice to open the json files individually, I tried this:


with open('./file_paths.txt') as file_list:
    for filename in file_list:
        json_data = json.load(file_list)

where in the './file_paths.txt' file I've got two paths listed like this:

./dataset_1.json,
./dataset_2.json

I have a comma separating them. I tried enclosing them in quotation marks but I'm still getting the same error:

json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

There is a problem with this line:

json_data = json.load(file_list)

in that I think the problem is how I've listed the filepaths in the .txt file.

surequestion
  • 3
  • 3
  • 1
    So... `filename` is a string containing a file name while `file_list` is the list of file names. How do you expect `json.load(file_list)` to work? Should be `json.load(filename)` or not? If not, why the loop? – Friedrich Mar 06 '23 at 13:41
  • You are passing the wrong argument to `json.load`, but the commas in your file aren't part of the file names, and will need to be stripped from each argument before passing it to `json.load`. – chepner Mar 06 '23 at 17:01

1 Answers1

0

The documentation for the json.load function (https://docs.python.org/3/library/json.html) refers to a single file or file-like object:

json.load(fp, *, cls=None, object_hook=None, parse_float=None,parse_int=None, parse_constant=None, object_pairs_hook=None, **kw)

Deserialize fp (a .read()-supporting text file or binary file containing a JSON document) to a Python object using this conversion table.

As you seem to want the loaded data from two files combined into one object, the answer here (https://stackoverflow.com/a/66059974/4438898) looks useful. It creates a 'merge_dict' function that combines two json-derived dictionaries into one, merging the entries where the keys are identical.

Reading a list of files and loading the json as a list of dicts

(Added in response to your replies)

This reads lines from mylistfile.txt line by line, strips the trailing '\n' from each line, then loads the json data from the resulting filename. The json data is added as a dictionary to the results list, and the results are printed:

Adding data from dataset_1.json
Adding data from dataset_2.json
Results: [{'hello': 1, 'there': 2}, {'key1': 1, 'key2': 2}]

mylistfile.txt was a 2 line file:

dataset_1.json
dataset_2.json
David Harrison
  • 26
  • 5
  • Can you take a look at this question and answer? This is where I got the idea from actually but there is no explanation about how the list of paths in the .txt file is constructed: https://stackoverflow.com/questions/22149972/how-to-open-multiple-file-paths – surequestion Mar 06 '23 at 11:09
  • Do you mean how to loop over a text file that contains a list of path/file names? That's a little different to your original question. Also, where do you want the contents of each json file to be stored: added to one large dictionary, or added as one item in a list of dictionaries? – David Harrison Mar 06 '23 at 11:19
  • Added as one item in a list of dictionaries. How can I store them in the text file? Comma separated? In strings or not? – surequestion Mar 06 '23 at 12:04
  • Please see the added section to my answer, above. If it fits the bill then please accept the answer. – David Harrison Mar 06 '23 at 16:53