plus/minus operator for python ±
Question: I am looking for a way to do a plus/minus operation in python 2 or 3. I do not
know the command or operator, and I cannot find a command or operator to do
this.

Am I missing something?


Answer: Another possibility: [uncertainties](http://pythonhosted.org/uncertainties/)
is a module for doing calculations with error tolerances, ie

    
    
    (2.1 +/- 0.05) + (0.6 +/- 0.05)    # => (2.7 +/- 0.1)
    

which would be written as

    
    
    from uncertainties import ufloat
    
    ufloat(2.1, 0.05) + ufloat(0.6, 0.05)
    

**Edit:** I was getting some odd results, and after a bit more playing with
this I figured out why: the specified error is not a tolerance (hard additive
limits as in engineering blueprints) but a standard-deviation value - which is
why the above calculation results in

    
    
    ufloat(2.7, 0.07071)    # not 0.1 as I expected!
    

