Python, Averages, and Division

Question

first = float(input("Enter first number: "));
second = float(input("Enter second number: "));
avg = float((first + second) / 2);
print(str(avg));

Using the numbers 1.1 and 1.3 as inputs, the expected output is 1.2. However, the result I'm receiving is 1.2000000000000002. I understand that this is related to Python and it's datatypes.

However, I'm unsure of how to evaluate this correctly, or why this specific result is achieved.

EDIT: Python 3.2

which python version is yours? I have 2.6.6 and with the same inputs I get 1.2 — cjdcordeiro, Sep 06 '13 at 15:13
This is not a python thing really, this is a IEEE float thing. — cmd, Sep 06 '13 at 15:15

score 3 · Accepted Answer · answered Sep 06 '13 at 15:11

3

Use decimals:

import decimal

first = decimal.Decimal('1.1')
second = decimal.Decimal('1.3')
avg = (first + second) / 2
print(avg)

answered Sep 06 '13 at 15:11

Noel Evans

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Python, Averages, and Division

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