The Kitchin Research Group

Python is a basic calculator out of the box. Here we consider the most basic mathematical operations: addition, subtraction, multiplication, division and exponenetiation. we use the to get the output. For now we consider integers and float numbers. An integer is a plain number like 0, 10 or -2345. A float number has a decimal in it. The following are all floats: 1.0, -9., and 3.56. Note the trailing zero is not required, although it is good style.

print 2 + 4
print 8.1 - 5

6
3.1

Multiplication is equally straightforward.

print 5 * 4
print 3.1*2

20
6.2

Division is almost as straightforward, but we have to remember that integer division is not the same as float division. Let us consider float division first.

print 4.0 / 2.0
print 1.0/3.1

2.0
0.322580645161

Now, consider the integer versions:

print 4 / 2
print 1/3

2
0

The first result is probably what you expected, but the second may come as a surprise. In integer division the remainder is discarded, and the result is an integer.

Exponentiation is also a basic math operation that python supports directly.

print 3.**2
print 3**2
print 2**0.5

9.0
9
1.41421356237

Other types of mathematical operations require us to import functionality from python libraries. We consider those in the next section.

Copyright (C) 2013 by John Kitchin. See the License for information about copying.

org-mode source