import numpy as np

GDP_2017 = 19519400000000
GDP_2016 = 18707200000000

GDP = np.array([GDP_2016, GDP_2017])

#Within the dictionary we have to set the datatype and format specification
np.set_printoptions(formatter={'int': '{:,}'.format})

print('Print the GDP and datatype after formatting')
print(GDP)
print(GDP.dtype)

#We reset the default settings
np.set_printoptions()

print('\nPrint the GDP and datatype after reset formatting')
print(GDP)
print(GDP.dtype)