Normally, we calculate power of a number as:

2

^{5}= 2 x 2 x 2 x 2 x 2 = 325

^{3}= 5 x 5 x 5 = 1259

^{2}= 9 x 9 = 81As we see, Python has a built-in function to calculate the power of a given number. Let's see:

## Definition of pow()

`pow()`

is a built-in function in Python that is used to compute the power of a given number. If the number is `x `

and the power is `y `

then `pow()`

returns `x `

to the power `y `

that is `x`^{y}

^{ }or

` x**y`

. The function `pow()`

takes three parameters `x `

which is the base number, `y `

which is the exponent and the third parameter `z `

which is optional is used to calculate the modulus that is `(x**y)% z`

pow(x,y) is equivalent to x**y that is x^{y}pow(x,y,z) is equivalent to (x**y)%z

## Syntax of pow()

```
pow(x,y,z)
```

Parameter | Description | Required/Optional |
---|---|---|

x | The base number | Required |

y | The exponent, that is the value of the power | Required |

z | The value to calculate the modulus | Optional |

Let's get to the examples of `pow()`

## Examples of pow()

```
p = pow(5, 3) # 5<sup>3</sup>
print(p)
q = pow(2, 5) # 2<sup>5</sup>
print(q)
r = pow(3, 4) # 3<sup>4</sup>
print(r)
```

125

32

81

Let's see whether it works with negative numbers as well:

```
p = pow(-2, 3)
print(p)
q = pow(2, -2)
print(q)
r = pow(-3, -2)
print(r)
```

-8

0.25

0.1111111111111111

Let's see some examples with the third parameter of pow():

```
p = pow(2, 3, 3) # (2**3)%3
print(p)
q = pow(5, 2, 4) # (5**2)%4
print(q)
r = pow(4, 4, 7) # (4**4)%7
print(r)
```

2

1

4

`pow()`

also works with floating numbers and other numeric formats too. Let's see:```
# binary
print(pow(0b1010, 2)) # 0b1010 = 100
# float
print(pow(2.2, 3))
# hexadecimal
print(pow(0x15, 2)) # 0x15 = 21
```

100

10.648000000000003

441