Python Forum

I have this program.
This question involves lines 25-51.
To solve the equations it has a long if\elif\else. I want to know if I can eliminate that by putting the operators in a list ["+", "-", "*", "/"] and use a for-loop to match them to a list like [add, sub, div, mult]?

something like:

text_in = StringVar()
add, sub, div, mult = solve
symbol_list = ["+", "-", "*", "/"]
operator_list = [add, sub, div, mult]

for i in range(len(symbol_list)):
    # select i from operator_list
    text_in.set(i)

I am probably showing my ignorance but...

It would be helpful to see your long elifs, but I can tell you that your symbol list is a list of strings, not mathematical operators.

If is common to see people make a function for each operation and then send numbers there. That might be a better option.

Of course. The standard library includes the operator module that has functions for those basic mathematical operations, e.g.

>>> import operator
>>> f = operator.add
>>> f(1, 2)
3
>>> f = operator.mul
>>> f(2, 3)
6
>>> 

It's really useful to be able to treat functions as values in the same way that, say, integers are values - being able to pass them around, or assign them to variables as I'm doing here.

Also, it sounds like having two separate lists is not what you want. Why not just have a dict that maps the symbol to the function instead?

@ndc85430, show you the operator module to use
In addition, look at https://python-forum.io/Thread-if-struct...dictionary
It show how to convert if/else into a dict. The tutorial defines its own functions, but as @ndc85430 said there is the convenient operator module