data_structures.stacks.prefix_evaluation¶

Python3 program to evaluate a prefix expression.

Attributes¶

`calc`
`test_expression`

`evaluate`(expression)	Evaluate a given expression in prefix notation.
`is_operand`(c)	Return True if the given char c is an operand, e.g. it is a number

data_structures.stacks.prefix_evaluation.evaluate(expression)¶

Evaluate a given expression in prefix notation. Asserts that the given expression is valid.

>>> evaluate("+ 9 * 2 6")
21
>>> evaluate("/ * 10 2 + 4 1 ")
4.0

data_structures.stacks.prefix_evaluation.is_operand(c)¶

Return True if the given char c is an operand, e.g. it is a number

>>> is_operand("1")
True
>>> is_operand("+")
False