import os
database = 'data.xls'
def get_database():
if not os.path.exists(database):
data = np.random.randint(-10000, 10000, size=1000)
pd_series = pd.Series(data, name='data')
pd_series.to_excel(database, engine='openpyxl')
else:
data = pd.read_excel(database, engine='openpyxl', index_col=0)
return data