Variables

• We created a variable, but what are variables?

• They are names that point to values

• We can change the value to which they point

>>> dogs = 2
>>> cats = 1
>>> dogs
2
>>> cats
1
>>> dogs > cats
True
>>> dogs = 1
>>> dogs > cats
False
>>> dogs = 3
>>> dogs
3
>>> dogs > cats
True
>>> cats + dogs
4

Exercise

• Create a number of variables and compare them in your interpreter.

• What type of names work as variables? Can you include spaces or punctuation?

• What is the difference between = and ==?

• Should we have named our variables dog_count and cat_count?

Extra Exercise

• What should the following print? (Try to answer without running it)

>>> a,b = 1,2
>>> b,a = a,b
>>> c,b = a,b
>>> b,b = b,c
>>> print b