text: """ Module for demonstrating examples of libraries usage """
  
  # all imports
  import json
  from requests import Session
  from requests.exceptions import ConnectionError,\
      Timeout, TooManyRedirects
  import pandas
  
  
  URL = 'https://pro-api.coinmarketcap.com/v1/cryptocurrency/listings/latest'
  
  parameters = {
      'start': '1',
      'limit': '5000',
      'convert': 'USD'
  }
  headers = {
      'Accepts': 'application/json',
      'X-CMC_PRO_API_KEY': '995673e7-a164-46dd-9e3c-0305ebf49bb5',
  }
  
  
  # TESTING MODULE JSON AND WRITING DATA INTO THE FILE
  # TESTING REQUESTS, MODULE SESSION AND EXCEPTIONS
  def write_into_file():
      """
      (NoneType) -> dict
      Get information using api, write into the file and
      print all the information..
      """
      session = Session()
      session.headers.update(headers)
      try:
          response = session.get(URL, params=parameters)
          data = json.loads(response.text)
          with open('data.json', 'w') as file:
              json.dump(data, file, ensure_ascii=False, indent=4)
          return data
      except (ConnectionError, Timeout, TooManyRedirects) as e:
          print(e)
  
  
  # TESTING PANDAS
  # CREATING TABLE WITH NEEDED DATA
  def testing_pandas():
      """
      (NoneType) -> NoneType
      Create a table with such data: name, symbol
      and price of each cryptocurrency.
      """
      data = write_into_file()
      names = []
      symbols = []
      price = []
      full_dict = {}
      for element in data['data']:
          names.append(element['name'])
          symbols.append(element['symbol'])
          price.append(element['quote']['USD']['price'])
      full_dict['NAME'] = names[:50]
      full_dict['SYMBOL'] = symbols[:50]
      full_dict['PRICE'] = price[:50]
      res = pandas.DataFrame.from_dict(full_dict, orient='columns')
      print(res)
  
  
  if __name__ == '__main__':
      print('TESTING PANDAS...')
      testing_pandas()
  