HW 1 - Variables, values and statements

CS 161 Homework 1

Bart Massey and Disha Gandhi


Here's some problems to test your understanding and

Problems 2 through 4 require computer programs: please place
each of these programs in a file with the name given in
square brackets. For example, problem 2 should be saved in a
file called "ctof.py".

Submit the assignment to the Moodle as a main text answering
all of the questions (problem 5 is optional) and attach
files containing the programs to the assignment.

  1. For each of the following variable names, indicate
    whether the name is (a) a good name for a variable,
    (b) valid Python but a bad name for a variable, or
    (c) not a legal Python variable name. Explain each
    answer in a sentence or so.

        1.1: _sport
    1.2: Iplaygamesallthetime
    1.3: 2_sports
    1.4: sport
    1.5: SPORT
  2. Celsius to Fahrenheit [ctof.py]:

    Write a program that inputs a temperature in degrees
    Celsius and prints that temperature in degrees
    Fahrenheit. If you don't know how to do the conversion,
    you can probably find out on the Internet. Credit your

  3. Echo EXTREME [echoextreme.py]:

    Write a program that inputs a string with the prompt
    "Yell something: ", and then outputs

        S!!!1! s!".'..

    where "S" is the uppercase version of that string, and
    "s" is the lowercase version. For example:

        Yell something: Hello
    HELLO!!!1! hello!".'..

    Note that your text should be formatted exactly like
    the text here---that is, with the same punctuation and

  4. Midway Point [midway.py]:

    In Python you can find the length of a string (the
    number of characters in it) by using the len()
    function. For example:

        >>> len('hello')

    Write a program that inputs a string with no prompt, and
    then outputs a line with a single caret character ("^")
    pointing at the middle character of that string. (If the
    string is of even length, round up.) For example:

  5. Optional Super Bonus Question:

    Try running each of the following programs. What happens?
    Explain why.


        x' = 3
    print('the variable x' has value ', x')


        print = 7
    print("the variable print has value ", print)


        print('the variable print has value', print)