LAB
Objectives
- becoming familiar with the concept of storing and working with different data types in Python
- experimenting with Python code.
Scenario
Here is a short story:
Once upon a time in Appleland, John had three apples, Mary had five apples, and Adam had six apples. They were all very happy and lived for a long time. End of story.
Your task is to:
- create the variables: john, mary, and adam
- assign values to the variables. The values must be equal to the numbers of fruit possessed by John, Mary, and Adam respectively
- having stored the numbers in the variables, print the variables on one line, and separate each of them with a comma
- now create a new variable named total_apples equal to addition of the three former variables
- print the value stored in total_apples to the console
- experiment with your code: create new variables, assign different values to them, and perform various arithmetic operations on them (e.g., +, /, // , etc. ). Try to print a string and an integer together on one line, e.g., "Total number of apples:" and total_apples.
Shortcut operators
It's time for the next set of operators that make a developer's life easier.
Very often, we want to use one and the same variable both to the right and the left sides of the = operator.
For example, if we need to calculate a series of successive values of powers of 2, we may use a piece like this:
x = x * 2
You may use an expression like this if you can't fall asleep and you're trying to deal with it using some good, old-fashioned methods:
sheep = sheep + 1
Python offers you a shortened way of writing operations like these, which can be coded as follows:
x *= 2
sheep += 1
Let's try to present a general description for these operations.
If op is a two-argument operator (this is a very important condition) and the operator is used in the following context:
variable = variable op expression
it can be simplified and shown as follows:
variable op= expression
Take a look at the examples below. Make sure you understand them all.
i = i + 2 * j ⇒ i += 2 * j
var = var / 2 ⇒ var /= 2
rem = rem % 10 ⇒ rem %= 10
j = j - (i + var + rem) ⇒ j -= (i + var + rem)
x = x ** 2 ⇒ x **= 2
