integral.py

def square(x):
    return x**2

def linear(x):
    return 2 * x + 1

def pow10(x):
    return x**10

def integral(f, h=0.001):
    """ definite integral: function of a, b """
    return lambda a, b: h * sum(f(a + i * h) for i in range(0, int((b - a) / h)))

def integral_mid(f, h=0.001):
    """ definite integral: function of a, b
    considering f's value in the middle of each interval"""
    return lambda a, b: h * sum(f(a + (i + 0.5) * h) for i in range(0, int((b - a) / h)))

# Derivative.
def diff(f, h=0.001):
    # when h not specified, default value h=0.001 is used
    return lambda x: (f(x + h) - f(x)) / h