That's all quite simple...
Spooky knows that each frequency is located either between the two commas, or between a double quote ( " ) and a comma ( and vice versa ), and then takes that number as a frequency. Now, such number can have a decimal portion ( decimal fraction ) or it can be an integer ( fractional component = 0 , therefore there's no need to use a decimal point ). Spooky handles them w/o a problem.
For more details, please check the link: