without an elsein that it is possible for no indented block to be executed this happens if none of the conditions in the tests are true with an else includedexactly one of the indented blocks is executed without an elseat most one of the indented blocks is executed if weight print('sorrywe can not take suitcase that heavy 'elif weight print('there is $ charge for luggage that heavy 'this if-elif statement only prints line if there is problem with the weight of the suitcase sign exercise write program sign py to ask the user for number print out which category the number is in'positive''negative'or 'zerograde exercise in idleload grade py and save it as grade py modify grade py so it has an equivalent version of the lettergrade function that tests in the opposite orderfirst for fthen dchinthow many tests do you need to do be sure to run your new version and test with different inputs that test all the different paths through the program be careful to test around cut-off points what does grade of implywhat about exactly wages exercise modify the wages py or the wages py example to create program wages py that assumes people are paid double time for hours over hence they get paid for at most hours overtime at times the normal rate for examplea person working hours with regular wage of $ per hour would work at $ per hour for hoursat $ for hours of overtimeand $ for hours of double timefor total of * * * * * $ you may find wages py easier to adapt than wages py be sure to test all paths through the programyour program is likely to be modification of program where some choices worked beforebut once you change thingsretest for all the caseschanges can mess up things that worked before nesting control-flow statements the power of language like python comes largely from the variety of ways basic statements can be combined in particularfor and if statements can be nested inside each other' indented blocks for examplesuppose you want to print only the positive numbers from an arbitrary list of numbers in function with the following heading read the pieces for now def printallpositive(numberlist)'''print only the positive numbers in numberlist '' tests to distinguish the casesas in the previous version if statements