Write a short python function to find out the average of three consecutive items

in an input list. The input of this function is a list of integer$/$ fractional values, and the function should

return a list of integer$/$ fractional values. The first item $($index $0)$ in the output list would be the average

value of the first three items $($index $0$ to $2)$ of the input list, the second item $($index $1)$ in the output list

would be the average value of the second three items $($index $3$ to $5)$ of the input list. For simplicity, assume

that the number of items in the input list will always be multiple of three. Write a main function to test

your function and print the output. Test with following examples at least.

Example $1$: Input $=[1,2,7,4,5,10],$ and output $=[3\mathrm{.}33,6\mathrm{.}33]$

Example $2$: Input $=[5\mathrm{.}5,6,8],$ and output $=[6\mathrm{.}5]$

Example $3$: Input $=[],$ and output $=[]$