error ‘list index is out of range’

my code is exactly as per given solution, but it is giving error : "list index is out of range"

code:

company_names =  ['Python DS', 'PythonSoft', 'Pythazon' 'Pybook']
key_name            =  ['open', 'high', 'low', 'close']
prices                   =  [[12.87, 13.23, 11.42, 13.10],[23.54, 25.76, 21.87, 22.33],[98.99, 102.34, 97.21, 100.065],[203.63, 207.54, 202.43, 205.24]]

d_1 = {}

for i in range(len(key_name)):

d_1[company_names[i]]= dict(zip(key_name,prices[i]))

print (d_1)

not getting why eroor is occuring.