Which type of programmer writes code for operating systems?

Python write an expression that executes the loop body as long as the user enters a non-negative number. note: if the submitted code has an infinite loop, the system will stop running the code after a few seconds and report "program end never reached." the system doesn't print the test case that caused the reported message. sample outputs with inputs: 9 5 2 -1

Working on this program in python 3.7: a year in the modern gregorian calendar consists of 365 days. in reality, the earth takes longer to rotate around the sun. to account for the difference in time, every 4 years, a leap year takes place. a leap year is when a year has 366 days: an extra day, february 29th. the requirements for a given year to be a leap year are: 1) the year must be divisible by 42) if the year is a century year (1700, 1800, the year must be evenly divisible by 400some example leap years are 1600, 1712, and 2016.write a program that takes in a year and determines whether that year is a leap year. ex: if the input is 1712, the output is: 1712 is a leap year. ex: if the input is 1913, the output is: 1913 is not a leap year. your program must define and call the function isleapyear(useryear). the function should return true if the input year is a leap year and false otherwise.

How do you make a lenny face? plz, brailiest to who can answer first.