Use pandas to make summary data

Make Summary data by pandas

with open('C:\\Users\\KaiyiLin\\Documents\\Alex\\MDM\\sales\\sales.json', 'r') as myfile:
    data=myfile.read()

obj = json.loads(data)

list1 = []
for item in obj:
    list1.append(item['fields'])

df1 = pd.DataFrame(list1)
sum1 = df1.groupby(['sales_calculate_date'])['quantity'].sum()
with open("C:\\Users\\KaiyiLin\\Documents\\Alex\\MDM\\sales\\file1.txt", "w") as output:
    output.write(str(sum1))

df_demo = df2.query("is_deleted == 'TRUE'")

df2_date = df2.set_index(['sales_calculate_date']) # make datetime field in panda searchable / filterable
df2_201904 = df2_date.loc['2019-04-01':'2019-04-30'] # search by range
df2_201904 = df2_date.loc['2019-04-01'] # search by equal
df1_201904.to_csv('C:\\Users\\KaiyiLin\\Documents\\Alex\\MDM\\sales\\file1.csv', sep='\t', encoding='utf-8') # export to csv