#### Solution to exercise 9.1 in the book

# class Line is from section 9.1.1 in the book 

class Line(object):
    def __init__(self, c0, c1):
        self.c0 = c0
        self.c1 = c1
        
    def __call__(self, x):
        return self.c0 + self.c1 * x
    
    def table(self, L, R, n):
        """Return a table with n points for L <= x <= R."""
        s = ""
        import numpy as np
        for x in np.linspace(L, R, n):
            y = self(x)
            s += "%12g %12g\n" % (x,y)
        return s

# The class below is from exercise 9.1 in the book
class Parabola0(Line):
    pass

# We create an instance of class Parabola0
p = Parabola0(0, 1)

# What is inside p?
print(dir(p))

# We see that the instance contains many special variables
# and methods of the form __NAME__ and also c0, c1, table.
# These are exactly the same attributes that we would find
# in an instance of class Line (as you can verify yourself
# by creating an instance q of class Line and perform dir(q)).
# The instance variables c0 and c1 and their values can
# also be seen by looking at the __dict__ variable:

print(p.__dict__)