Boolean values most often arise from comparison operators. Python includes a variety of operators that compare values. For example,
3 is larger than
1 + 1.
3 > 1 + 1
True indicates that the comparison is valid; Python has confirmed this simple fact about the relationship between
1+1. The full set of common comparison operators are listed below.
|Comparison||Operator||True example||False Example|
|Less than||<||2 < 3||2 < 2|
|Less than or equal||<=||2 <= 2||3 <= 2|
|Greater or equal||>=||3 >= 3||2 >= 3|
|Equal||==||3 == 3||3 == 2|
|Not equal||!=||3 != 2||2 != 2|
An expression can contain multiple comparisons, and they all must hold in order for the whole expression to be
True. For example, we can express that
1+1 is between
3 using the following expression.
1 < 1 + 1 < 3
The average of two numbers is always between the smaller number and the larger number. We express this relationship for the numbers
y below. You can try different values of
y to confirm this relationship.
x = 12 y = 5 min(x, y) <= (x+y)/2 <= max(x, y)
Strings can also be compared, and their order is alphabetical. A shorter string is less than a longer string that begins with the shorter string.
"Dog" > "Catastrophe" > "Cat"