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Section 2.5 Operators and operands

Operators are special symbols that represent computations like addition and multiplication. The values the operator is applied to are called operands.
The operators +, -, *, /, and ** perform addition, subtraction, multiplication, division, and exponentiation, as in the following examples:
There was a change in the division operator between Python 2.x and Python 3.x. In Python 3.x, the result of this division is a floating point result:
The division operator in Python 2.0 would divide two integers and truncate the result to an integer:
>>> minute = 59
>>> minute/60
0
To obtain the same answer in Python 3.0 use floored ( // integer) division.
In Python 3.0 integer division functions much more as you would expect if you entered the expression on a calculator.

Checkpoint 2.5.1.

    csp-10-2-4: What is the result of 3 / 4?
  • 0
  • If the two values are both integers (whole numbers) you will normally get an integer (whole number) result in older Python environments. But, this book is using Python 3 so you get a decimal result.
  • 1
  • This would be correct if the result was rounded up before the values after the decimal point were thrown away, but it does not do this.
  • 0.75
  • While this isn't the what older Pyton development environments would return, in this book we are using Python 3 so it returns a decimal result.
  • 0.25
  • This would be correct if it was 1 / 4, 1.0 / 4, or 1 / 4.0

Checkpoint 2.5.2.

csp-10-2-5: What operator (symbol) would you use to truncate division in Python 3.0?

Checkpoint 2.5.3.