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`

.

In [1]:

```
3 > 1 + 1
```

Out[1]:

The value `True`

indicates that the comparison is valid; Python has confirmed this simple fact about the relationship between `3`

and `1+1`

. The full set of common comparison operators are listed below.

Comparison | Operator | True example | False Example |
---|---|---|---|

Less than | < | 2 < 3 | 2 < 2 |

Greater than | > | 3>2 | 3>3 |

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 `1`

and `3`

using the following expression.

In [2]:

```
1 < 1 + 1 < 3
```

Out[2]:

The average of two numbers is always between the smaller number and the larger number. We express this relationship for the numbers `x`

and `y`

below. You can try different values of `x`

and `y`

to confirm this relationship.

In [3]:

```
x = 12
y = 5
min(x, y) <= (x+y)/2 <= max(x, y)
```

Out[3]:

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.

In [4]:

```
"Dog" > "Catastrophe" > "Cat"
```

Out[4]: