Say I had a list number_list = [3,4,9]
And I wanted to operate on the numbers in the list based on a list such as operators = ['+', '-']
This program would take these lists and operate on the numbers using the list. Using the example lists, the following would be equated:
3 + 4 - 9
And the function would return the result of this equation.
Whilst I know the order for plus and minus operations does not matter, I plan on using this with multiplication and division as well, where order does matter.
Thank you to anyone who can provide some insight as to how I would do this.
>Solution :
Lazy solution that does not care about security (read up on the "bad things" eval can do)
number_list = [3, 4, 9, 5]
operators = ["+", "-", '*']
# create a new list that can hold the above lists
new = [None] * (len(number_list) + len(operators))
# assign the first list using slice assignment
new[::2] = number_list
# assign the second list using slice assignment
new[1::2] = operators
# make all the elements to a string and eval
res = eval(''.join(map(str, new)))
print(res)
Output
-38
Assumption
operators must have valid operators and must be exactly one less than the size of number_list. Again, eval is not the way to go if you are doing this in actual production code.