Introduction
 A gradient describes how much y changes relative to a change in x.

For example, we can define a line as starting at (0, 0) and ending at (10, 25):
 Instead of giving explicit start and end points for the line we can describe it by how much y changes relative to x.
 In the line above, a change of 10 in x produces a change of 25 in y.
 The gradient is defined as the change in y divided by the change in x.

If we use Δ to denote 'change' then the formula for the gradient (g) of a line is:
LaTeX:g = \frac{\Delta y}{\Delta x}

In the line above, the gradient is:
Finding the change in x and y
 In our above example, our first coordinate was (9, 0). This made it easy to calculate how much x and y changed.
 However when both coordinates are nonzero, it gets a bit more complicated.

For example, calculate the gradient of the line between (1, 2) and (7, 10)
 To find how much x and y change, we need to subtract the first coordinate from the second



We can use this in our equation to find the gradient of a line:
Special Cases

There are two special cases to look out for when calculating the gradient of a line:

When the line is horizontal
 There will be no change in y
 The gradient is 0

When the line is vertical
 There will be no change in x
 The gradient is infinity

When the line is horizontal
Code
import math
def findGradient(p1, p2):
deltaY = p2[1] = p1[1]
deltaX = p2[0]  p1[0]
if deltaX == 0:
return math.inf
else:
return deltaY / deltaX
gradient = findGradient([1, 2], [7, 10])
print(gradient) # prints 0.3333333333333333