# Checking Numeric Ranges

**00:00**
In this lesson, you’ll see another example of using `and`

to determine if a value is within a numeric range. Plus, see a feature of Python which can simplify these types of expressions.

**00:12**
As you’ve seen before, `and`

is frequently used to connect conditions which describe the lower and upper limits of a range of numbers. To be between `0`

and `10`

inclusively, a number must be at least `0`

and less than or equal to `10`

.

**00:27**
This file, called `range.py`

, has this function defined, using default values for the lower and upper limits, but allowing specific ones to also be provided. You can see how it works.

**00:45**
you can call it a few times. `5`

is greater than or equal to `0`

, and it’s less than or equal to `10`

. Since both our expressions are true, the `and`

of them is `True`

, and this function will return `True`

.

**01:03**
`20`

is greater than or equal to `0`

, but it is not less than or equal to `10`

. So that part is false, making the `and`

of both of them `False`

, so this function returns `False`

.

**01:16**
You can test if a number is in a different range by supplying values for those parameters. In this case, `20`

is greater than or equal to `10`

, and it is less than or equal to `40`

, so the whole thing is true.

**01:34**
`and`

is used when you want to check if a number is within a certain range. However, if you want to check if a value is outside a given range, you have to use `or`

. If a number is not within the range of `0`

to `10`

inclusively, then it’s either less than `0`

or greater than `10`

.

**01:55**
It can’t be both. So you have to use `or`

, where the `or`

of two expressions is `True`

if at least one of those expressions is true.

**02:04**
There is a tutorial and a video course on how to use Python’s `or`

operation here at Real Python. As you’ve seen, these types of `and`

conditions are quite frequent.

**02:15**
So Python has actually defined a simpler syntax when you want to use one. Perhaps you recall from math that the compound inequality `0 ≤ x and x ≤ 10`

can be shortened to `0 ≤ x ≤ 10`

.

**02:34**
You can do this in Python as well. The expression `0 <= x <= 10`

is valid in Python. So I could replace the `and`

operation in this function with `start <= number <= end`

. Save this, restart the REPL, and import it again.

**03:11**
And the previous interactions should work the same.

**03:28**
And they do. Please notice that most other languages do not allow this syntax. Next, and finally, you’ll look at how `and`

can be used to chain function calls where one function call actually depends on the success of a previous one.

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