I want to create a json file like this:

{"946705035":4,"946706692":4 ...}

I am taking a column that only contains Unix Timestamp and group them.

result = data['Last_Modified_Date_unixtimestamp_no_time'].value_counts()In [21]: result.head()
Out[21]: 
1508284800    131
1508716800    106
1508371200    101
1508457600     99
1508630400     96
Name: Last_Modified_Date_unixtimestamp_no_time, dtype: int64

transform to a dict

result = result.to_dict()
result
'''
{1507161600: 1,1507852800: 1,1508198400: 64,1508284800: 131,...1535155200: 1,1535241600: 1}
'''import json
result = json.dumps(result)with open('result.json', 'w') as fp:json.dump(result, fp, indent=4)

result this is the data structure that I expected

{"946705035":4,"946706692":4}

You're dumping the JSON twice, which causes quotes to be escaped on the second dump. (After the first json.dumps the result is only a string, so you're just dumping a string instead of a dict again)

import json
# result = json.dumps(result)with open('result.json', 'w') as fp:json.dump(result, fp, indent=4)

Or remove the second dump:

import json
result = json.dumps(result)with open('result.json', 'w') as fp:# json.dump(result, fp, indent=4)print(result, file=fp)