Getting data from E-vergabe NRW API

vergabe_nrw.ipynb

import requests 
import pandas as pd
import numpy as np
import json
import janitor
from tabulate import tabulate

#show all columns
pd.set_option('display.max_columns', None)
pd.set_option('display.max_rows', None)

np.set_printoptions(threshold=np.inf)

url = 'https://daten.vergabe.nrw.de/rest/vmp_rheinland_single/aggregation_search/'
 
headers = {'Accept': 'application/json', 'Content-Type': 'application/json'}

#According to documentation, there was a limit of 10.000
params = {'size': 10000}
 
req = requests.post(url, headers=headers, params=params)

# Retrieving data
json_data = json.loads(req.text)
#json_data
df = pd.json_normalize(json_data['results'])
nomes = df.columns
nomes = nomes.str.replace('result\.', '')
df.columns = nomes
df = df.iloc[:,1:19]
df = df.clean_names()

print('GENERAL INFORMATION: \n\n rows and columns number:', df.shape, 
     '\n older creation data:', df.created_at.min(),
     '\n newer creation data:', df.created_at.max())
     
# GENERAL INFORMATION: 
# rows and columns number: (5817, 18) 
# older creation data: 2019-11-19T07:19:15.448Z 
# newer creation data: 2021-04-03T22:19:51.775Z

# Looking at null values:

nv = pd.DataFrame(df.isnull().sum())
nv.columns = [ 'total_null_values']
nv