Merging multiple JSON files using Python I have multiple (1000+) JSON files each of which contain a JSON array. I want to merge all these files into a single file.

I came up with the following, which reads each of those files and creates a new object with all the contents. I then write this new object into a new file.

Is this approach efficient? Is there a better way to do so?

head = []
with open("result.json", "w") as outfile:
    for f in file_list:
        with open(f, 'rb') as infile:
            file_data = json.load(infile)
            head += file_data
    json.dump(head, outfile)
First off, if you want reusability, turn this into a function. The function should have it's respective arguments.
Secondly, instead of allocating a variable to store all of the JSON data to write, I'd recommend directly writing the contents of each of the files directly to the merged file. This will help prevent issues with memory.
Finally, I just have a few nitpicky tips on your variable naming. Preferably, head should have a name more along the lines of merged_files, and you shouldn't be using f as an iterator variable. Something like json_file would be better.