math.sqrt

Returns the square root of a number.

Synopsis

import math
math.sqrt(number)

Description

sqrt lives in the math module, so the file needs import math before you use it.

Parameters

Return value

A float, even for a perfect square.

Example

import math

print(math.sqrt(16))
print(math.sqrt(2))

It prints:

4.0
1.4142135623730951

Common mistake

print(math.sqrt(16))

Python stops with:

NameError: name 'math' is not defined. Did you forget to import 'math'

The file is missing import math at the top.

See also

math.floor, math.ceil, round

math.sqrt in the Python documentation