How to pass an operator to a python function?

Question

I'd like to pass a math operator, along with the numeric values to compare, to a function. Here is my broken code:

def get_truth(inp,relate,cut):         if inp print(relate) cut:         return True     else:         return False 

and call it with

get_truth(1.0,'>',0.0) 

which should return True.

Answer 1

Have a look at the operator module:

import operator get_truth(1.0, operator.gt, 0.0)  ...  def get_truth(inp, relate, cut):         return relate(inp, cut)     # you don't actually need an if statement here 

Answer 2

Make a mapping of strings and operator functions. Also, you don't need if/else condition:

import operator   def get_truth(inp, relate, cut):     ops = {'>': operator.gt,            '<': operator.lt,            '>=': operator.ge,            '<=': operator.le,            '==': operator.eq}     return ops[relate](inp, cut)   print(get_truth(1.0, '>', 0.0)) # prints True print(get_truth(1.0, '<', 0.0)) # prints False print(get_truth(1.0, '>=', 0.0)) # prints True print(get_truth(1.0, '<=', 0.0)) # prints False print(get_truth(1.0, '==', 0.0)) # prints False 

FYI, eval() is evil: Why is using 'eval' a bad practice?