# -*- coding: utf-8 -*-

"""

Created on Wed May 10 19:51:47 2017

@author: Raghav Bali

"""

"""

This script showcases methods to read JSON type data:

+ using python's inbuilt utilities

+ using pandas

``Execute``

$ python read_json.py

"""

import json

import pandas as pd

def print_nested_dicts(nested_dict,indent_level=0):

"""This function prints a nested dict object

Args:

nested_dict (dict): the dictionary to be printed

indent_level (int): the indentation level for nesting

Returns:

None

"""

for key, val in nested_dict.items():

if isinstance(val, dict):

print("{0} : ".format(key))

print_nested_dicts(val,indent_level=indent_level+1)

elif isinstance(val,list):

print("{0} : ".format(key))

for rec in val:

print_nested_dicts(rec,indent_level=indent_level+1)

else:

print("{0}{1} : {2}".format("\t"*indent_level,key, val))

def extract_json(file_name,do_print=True):

"""This function extracts and prints json content from a given file

Args:

file_name (str): file path to be read

do_print (bool): boolean flag to print file contents or not

Returns:

None

"""

try:

json_filedata = open(file_name).read()

json_data = json.loads(json_filedata)

if do_print:

print_nested_dicts(json_data)

except IOError:

raise IOError("File path incorrect/ File not found")

except ValueError:

ValueError("JSON file has errors")

except Exception:

raise

def extract_pandas_json(file_name,orientation="records",do_print=True):

"""This function extracts and prints json content from a file using pandas

This is useful when json data represents tabular, series information

Args:

file_name (str): file path to be read

orientation (str): orientation of json file. Defaults to records

do_print (bool): boolean flag to print file contents or not

Returns:

None

"""

try:

df = pd.read_json(file_name,orient=orientation)

if do_print:

print(df)

except IOError:

raise IOError("File path incorrect/ File not found")

except ValueError:

ValueError("JSON file has errors")

except Exception:

raise

if __name__=='__main__':

print("\n\n")

print("*"*30)

print("Contents of sample json file:")

print("*"*30)

extract_json(r'sample_json.json')

print("\n\n")

print("*"*30)

print("Contents of a json file using pandas:")

print("*"*30)

extract_pandas_json(r'pandas_json.json')