Making a more in depth python calculator

Question

first = input("first #:")
operator = input("operator: ")
second = input("second #:")


is_float = true ? false

if (is_float == true) {
 first = float()
 second = float()

} else if (is_float == false) {
  first = int()
  second = int()
}

print(first + operator + second )

I am practicing python and i want to make a more indepth calculator that has 2 numbers and various operators for adding subtracting multiplying etc and i want it to switch between a true or false boolean whether or not its a float number. im not quite sure how to do this would someone be willing to explain how booleans work in python? I completely understand not spoon feeding but im not sure how to finish this

`is_float = true ? false` What is this supposed to mean? Is this meant to be actual code? — John Gordon, Apr 23 '23 at 18:53
You can check for the presence of a decimal point in the input string. If there is one, then you can assume the value is a float, otherwise you can assume integer. — John Gordon, Apr 23 '23 at 18:56
@JohnGordon scientific notation may not have decimal point in it. [This answer](https://stackoverflow.com/questions/736043/checking-if-a-string-can-be-converted-to-float-in-python) describes correct way the best I guess. Although there is no clear question of what OP is struggling to achieve — sudden_appearance, Apr 23 '23 at 19:01
Your first problem is that the code you are writing isn't Python. — mkrieger1, Apr 23 '23 at 19:02

score 0 · Accepted Answer · answered Apr 23 '23 at 19:02

0

input() returns a string, so you can check for the presence of a decimal point.

If there is one, use float() to convert the input string, otherwise use int().

if '.' in first:
    first = float(first)

else:
    first = int(first)

answered Apr 23 '23 at 19:02

John Gordon

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There'd also better be first.isnumeric() before if-else I think – sudden_appearance Apr 23 '23 at 19:03
@sudden_appearance A decimal point would make that automatically false, would it not? Also I think you meant `isdigit()`. – John Gordon Apr 23 '23 at 19:04
Oh, you are right, it does result in False. – sudden_appearance Apr 23 '23 at 19:05

Jord van Eldik · Answer 2 · 2023-04-23T18:59:49.473

-1

You could check if the floor value of the number differs from the number itself, giving is_float = (first - math.floor(first) < 0.00001), in this second case you will have to import the math package as import math at the top of your file.

But you will have to parse a number from the input like this:

first  = float(input("first #:"))
second = float(input("second #:"))

You cast the inputs to floats, and then chck if the floats are not just 'whole numbers'.

edited Apr 23 '23 at 18:59

answered Apr 23 '23 at 18:54

Jord van Eldik

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`is_float = isinstance(first, float)` This can't work, because it presumes the code has _already_ decided to call `int()` or `float()` on the user input string. But the question is -- how does the code _make_ that decision in the first place? – John Gordon Apr 23 '23 at 18:55
soryy you're right – Jord van Eldik Apr 23 '23 at 18:56

Making a more in depth python calculator

2 Answers2