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An Actual Calculator
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RyanMuraliraj

It is mind blowing how no one has created a calculator where you just type in an expression and get the result. All of the calculators I've seen have you type in one number then press enter then type in +, -, / or * then press enter then type your second number. This calculator takes simple expressions and returns the result.

Examples:
Input:1+1 | Output:2
Input:1000-15 | Output:985
Input:10*10 | Output:100
Input:100/10 | Output:10
Input:2/3 | Output:0.666666
Input:0/0 | Output: Error

*No spaces in expressions
**Can do addition, subtraction, multiplication, and division. Planning to add more operations in the future.
***Has float/int switcher in division. If is not a whole number it is a float, if it is a whole number it is an int.

My Calculator:
https://repl.it/@RyanMuraliraj/Calculator

Some of the calculators I was talking about:
https://repl.it/ibuiltthis/p/my-calculator-1
https://repl.it/ibuiltthis/p/calculator
https://repl.it/@HongjiDai/Simple-Calculator

This calculator does it but uses external modules without actually coding it themself:
https://repl.it/ibuiltthis/p/mega-calculator

Shoutout to the creators of the calculators listed above for the idea and inspiration.

pls upvote

Voters
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XanthusPettitt
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BetaGamer
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Maxstrobe
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RyanMuraliraj
Comments
hotnewtop
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XanthusPettitt

wow mate! this is super cool

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ApoorvAgrawal

You could use the .strip() function to get rid of the spaces that come with the user input.
and maybe you could add a space after the colon to make it look better.
like get=input("Input:").strip(' ')

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proofofconcept

This calculator does not use eval but can evaluate arbitrary length expressions, with parentheses. It supports floats.
https://repl.it/@proofofconcept/Basic-recursive-descent-parser

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RyanMuraliraj

@proofofconcept
: I don't know man, I put 2-1 into your calculator and I got -1. I also put 3/2 and I got nan. Regardless, I'm impressed.

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RyanMuraliraj

@proofofconcept
: I take it back, I tried again and it works perfectly. A suggestion would be to switch the float to a int if a decimal is not needed such as 10.0 or 2.0 would become 10 or 2.

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proofofconcept

@ryanmuraliraj
: The calculator now supports variables
You type x=0 for example, and then you can use x in expressions
However variable names can only be one letter long

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RyanMuraliraj

@proofofconcept
: Nice. If you post your calculator on I built this I'll upvote.

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proofofconcept

@ryanmuraliraj
: Ok, I posted it, and added some things as well. This could turn into a programming language if I keep adding these things!

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Rapax_Brak

@proofofconcept
: Really well done gg fam

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FanjinMeng
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RyanMuraliraj

@fanjinmeng
: That is great, however you used the eval function to do it for you, I hardcoded mine.

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RyanMuraliraj

@fanjinmeng
: Plus, not to put down someone who might be new to programming, but you can make your calculator even simpler and make it 2 lines. Also, because your code is 4 lines, if someone types in something that is mathematically impossible such as 0/0 the program crashes.

My version that is 2 lines (also crashes when inputted 0/0):
https://repl.it/@RyanMuraliraj/The-Actual-Simplest-Calculator-in-the-World

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proofofconcept

@ryanmuraliraj
: Using list comprehensions you can do it in one line:
[print("Result: "+str(eval(input("Enter expression: " )))) if x else print("Welcome to the single line calculator") for x in range(2)]

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Nosrep

@proofofconcept
: a simpler one:
print(eval(input('calculation here:')))

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Nosrep

@ryanmuraliraj
: another version that can do it in 1 line:
print(eval(input("calculation here:")))
non-crashing version:
try:
print(eval(input("calculation:")))
except:
print("INVALID")

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Rapax_Brak

@fanjinmeng
: the eval function is very dangerous as well and someone could do a buffer overflow attack.