"""
Trace statements illustrating control statment flow

Trace statements are just print statements that tell us
where we are in the code.  They are distinct from a
watch, which tells us the current contents of a variable.

Author: Walker M. White
Date:   August 31, 2017 (Python 3 Version)
"""


def max2(x,y):
    """
    Returns: max of x, y
    
    Shows of flow of if-else
    """
    # Put max of x, y in z
    print('before if')
    if x > y:
        print('if x>y') # trace
        z  = x
        print('z is '+str(z)) # watch
    else:
        print('else x<=y')
        z  = y
        print('z is '+str(z)) # watch
    print('after if')
    return z


def max3(x,y,z):
    """
    Returns: max of x, y, z
    
    Shows of flow of if-elif-else
    """
    # Put max of x, y, z in w
    print('before if')
    if x > y and x > z:
        print('if x>y and x>z') # trace
        w  = x
        print('w is '+str(w)) # watch
    elif y > z:
        print('elif y>z and y>=x') # trace
        w  = y
        print('w is '+str(w)) # watch
    else:
        print('else z>=x and z>=y')
        w  = z
        print('w is '+str(w)) # watch
    print('after if')
    return w