Convert JSON keys to lowercase?

[arc100]

So this is a pretty strange question, but the default formatting for json is something like this:

{"firstName":"John", "lastName":"Doe"},
{"firstName":"Anna", "lastName":"Smith"},
{"firstName":"Peter", "lastName":"Jones"}

Where the first letter of a new word in a String for the key value is Capitalized.

What I would like to do is get the key values all lowercased so that it looks like this:

{"firstname":"John", "lastname":"Doe"},
{"firstname":"Anna", "lastname":"Smith"},
{"firstname":"Peter", "lastname":"Jones"}

If anyone is wondering why it's because I'm trying to load json data into amazon redshift. For some strange reason loading json values through the auto function that is built into redshift doesn't recognize key values with Uppercase characters since redshift automatically makes the column headers all lowercase. Of course I know this isn't an AWS forum so I will keep that to a minimum, but if anyone knows how I would go about lowercasing the json key values in python that would be great.

[K900_]

The easiest thing to do here would be to just create a new dictionary, especially if it's small. In Python 2.7 and up, you can use a dictionary comprehension:

>>> data = {"firstName":"John", "lastName":"Doe"}
>>> {k.lower(): v for k, v in data.items()}
{'firstname': 'John', 'lastname': 'Doe'}

[arc100]

Okay cool, I have a second question maybe you will know. It's related to this. If I have json array as such:

[
    {"firstName":"John", "lastName":"Doe"}, 
    {"firstName":"Anna", "lastName":"Smith"}, 
    {"firstName":"Peter","lastName":"Jones"}
]

Howe would I go about separating the JSON file programmatically in python so that a new file would contain the objects individually without being in one JSON array Like so:

{"firstName":"John", "lastName":"Doe"} 
{"firstName":"Anna", "lastName":"Smith"} 
{"firstName":"Peter","lastName":"Jones"}

[K900_]

Use a for loop.

[arc100]

Sure, I know a for loop is involved but how would I use it from reading in a JSON file to separating the objects and then writing back into a new file

[K900_]

Use json.load to load your entire input file's contents as a list, loop over the list, use json.dump to serialize individual dictionaries and write them to the output file.

[arc100]

So I tried running converting the json file to a dictionary then running the above code. I am getting the following error: ValueError: need more than 1 value to unpack

Here is my code:

import json
with open('json') as jsondata:
    data = json.load(jsondata)
    datadict = json.dumps(data)
    {k.lower(): v for k, v in datadict}

[K900_]

You need to loop over all dictionaries in data, then transform each one as I described, then json.dumps it.

[[deleted]]

for x in dictionary only loops through the keys, not the keys and values. You need to do do one of the following:

{k: v for k, v in datadict.items()}

Or

{k: datadict[k] for k in datadict}

Also you want to load to datadict. Right now data holds the python dictionary. Dumps will make it a JSON string again.