An interesting feature of the Python code is that it uses metaclasses. A metaclass is to a class as a class is to an object. 

The Python code uses classes rather than labels for the roads: A, B, C. A road segment of length n on road A is A(n), i.e., an instance of Road A. But the roads themselves are often treated as objects, e.g., when one wants to define their __str__() methods. The way to do that is to define such methods in the Metaclass.

The Haskell code uses a number of user-created operators. We can't do that in Python, but we can repurpose operators.  The function to join two Paths into a single combined Path is given to the (+) operator. Doing that required defining the __add__() method in the Path class. The (+) operator is used to join two paths in the bestPath method. If p1 and p2 are Paths, p1 + p2 is the combined path. The expression p1 + p2 is executed as p1.__add__(p2).

You can do the same thing with numbers: 

>>> (1).__add__(2)
3

(Leaving out the parentheses around the 1 produces a syntax error.)

Similarly,

>>> (1+2).__add__(3)
6

As the Python documentation says, everything is an object, even numbers.