Question

This is a question for a homework problem that I cant figure out:

Question Beginning

Q3. Let’s try to write a function that does the same thing as an if statement:

def if_function(condition, true_result, false_result):

    """Return true_result if condition is a true value, and false_result otherwise."""

    if condition:
        return true_result
    else:
        return false_result

This function actually doesn’t do the same thing as an if statement in all cases. To prove this fact, write functions c, t, and f such that one of these functions returns the number 1, but the other does not:

def with_if_statement():

    if c():
        return t()
    else:
        return f()

def with_if_function():

    return if_function(c(), t(), f())

Question End

Heres what I figured out:

with_if_statement() does not evaluate f() if c() is true, but with_if_function() evaluates all 3 before checking if c() is true or not.

So, I thought of assigning a global variable in c(), and changing its value in f()

heres my code (which does not work):

def c():

    try:
        global x
    except NameError:
        x=1
    if x==1:
        return True
    else:
        return False

def t():

    if x==1:
        return (1)
    else:
        return (0)

def f():

    global x
    x=2
    if x==1:
        return (1)
    else:
        return (0)

can anyone help me figure out the answer? Thanks..!

Answer 1

The global statement shouldn’t throw a NameError (and so you won’t run x=1 in c()). I would try rewriting your code without using exceptions, they won’t be necessary to solve this and are making it more complicated than it needs to be. Using a global variable and having side effects in your functions is certainly the right track.