Generating 7-digit 10 million numbers in python [closed]

In python,How can I generate 10 million random 7 digit numbers in 30 seconds?

333 will be written at the beginning of the generated numbers. For example, a number will be output like this;

333-435-4578
333-267-1323
333-932-5894

but the first digit will not start with zero. So these are wrong;

333-043-2348
333-056-3455

How to generate 10 million units in under 30 seconds in this way?