expression

Contains functionality for dealing with expressions.

Exports:

>>> from pylp.expression import Expression

class pylp.expression.Expression(operator: str, operands: list)

Represents an expression in a linear programming problem.

Notes

A list of operands is given in order to reduce the height of the expression tree.

Normally, an operator operates on two operands. Thus the expression:

5 + 5 + 5

can be represented as a tree:

/ 5 +

/ 5 5

But as the expression gets longer, a naive approach would result in a very tall tree. In order to evaluate the tree, we would have to traverse all the way to its leafs, which at its deepest part would probably result in a stack overflow (maximum recursion error).

But treating the operands as a list, results in a nicer tree:

/ | 5 5 5

And this tree stays at the same height the more operands it holds.

This prevents a stack overflow from occurring. This also results in better performance as well.

construct()

Build the expression for use in the solver.

evaluate()

Evaluate the expression.

is_same_type(other: Expression) → bool

Return True if the other expression is of the same type.