Python has four ways to calculate the `n`

-th power (exponent) of `x`

so that `xⁿ=x*x*...*x`

that multiplies the base `x`

with itself, and repeating this `n`

-times.

**Method 1**: Use the double-asterisk operator such as in`x**n`

.**Method 2**: Use the built-in`pow()`

function such as in`pow(x, n)`

.**Method 3**: Import the math library and calculate`math.pow(x, n)`

.**Method 4**: Import the NumPy library and calculate`np.power(x, n)`

.

Let’s dive into these four methods one by one!

## Method 1: Double-Asterisk x**n

The double asterisk (**) symbol is used as an exponentiation operator. The left operand is the base and the right operand is the power. For example, the expression `x**n`

multiplies the value `x`

with itself, `n`

times.

Let’s have a look at a couple of simple examples:

>>> 2**2 4 >>> 2**3 8 >>> 2**4 16 >>> 2**5 32 >>> -3**3 -27

You can also raise to a negative power in which case, the whole expression is inverted such that `x**-n == 1/(x**n)`

.

>>> 2**-3 0.125 >>> 2**-2 0.25

## Method 2: Built-In pow(x, n)

For `pow(x, y)`

, the `pow()`

function returns the value of `x`

raised to the power `y`

. It performs the same function as the power operator `**`

, i.e. `x**y`

, but differs in that it comes with an optional argument called `mod`

.

Parameter | Description |

exp | A number that represents the base of the function, whose power is to be calculated. |

base | A number that represents the exponent of the function, to which the base will be raised. |

mod | A number with which the modulo will be computed. |

Here are a couple of examples without the `mod`

argument:

>>> pow(5, 2) 25 >>> pow(-3, 3) -27 >>> pow(2, -2) 0.25

If we have a `mod`

argument such as `z`

in `pow(x, y, z)`

, the function first performs the task of raising `x`

to the power `y`

and then that result is used to perform the modulo task with respect to `z`

. It would be the equivalent of `(x**y) % z`

.

Here are three examples with the mod argument:

>>> pow(14, 7, 5) 4 >>> pow(-8, 3, 5) 3 >>> pow(2, 4, -3) -2

## Method 3: math.pow(x, n)

The `math.pow(x, n)`

function raises `x`

to the power of `n`

. It calculates the exponent function. The difference to the built-in `pow()`

function is that it doesn’t allow the optional mod argument and it always returns a float, even if the input arguments are integers.

Consider the following examples that show how to use it with integer arguments, float arguments, negative bases, and negative exponents:

>>> math.pow(2, 3) 8.0 >>> math.pow(2.3, 3.2) 14.372392707920499 >>> math.pow(-2, 3) -8.0 >>> math.pow(2, -3) 0.125

## Method 4: numpy.power(x, n)

The NumPy library has a `np.power(x, n)`

function that raises `x`

to the power of `n`

. While the inputs can be arrays, when used on numerical values such as integers and floats, the function also works in the one-dimensional case.

>>> np.power(2, 2) 4 >>> np.power(2, 3) 8 >>> np.power(-2, 3) -8 >>> np.power(2.0, -3) 0.125

However, if you try to raise an integer to a negative power, NumPy raises an error:

>>> np.power(2, -3) Traceback (most recent call last): File "<pyshell#25>", line 1, in <module> np.power(2, -3) ValueError: Integers to negative integer powers are not allowed.

To fix it, convert the first integer argument to a float value, for example using the `float()`

function.

## Summary

You’ve learned four ways to calculate the exponent function in Python.

**Method 1**: Use the double-asterisk operator such as in `x**n`

.

**Method 2**: Use the built-in `pow()`

function such as in `pow(x, n)`

.

**Method 3**: Import the math library and calculate `math.pow(x, n)`

.

**Method 4**: Import the NumPy library and calculate `np.power(x, n)`

.

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## Arithmetic Operators

Arithmetic operators are syntactical shortcuts to perform basic mathematical operations on numbers.

Operator | Name | Description | Example |
---|---|---|---|

+ | Addition | Calculating the sum of the two operands | `3 + 4 == 7` |

-- | Subtraction | Subtracting the second operand from the first operand | `4 - 3 == 1` |

* | Multiplication | Multiplying the first with the second operand | `3 * 4 == 12` |

/ | Division | Dividing the first by the second operand | `3 / 4 == 0.75 ` |

% | Modulo | Calculating the remainder when dividing the first by the second operand | `7 % 4 == 3` |

// | Integer Division, Floor Division | Dividing the first operand by the second operand and rounding the result down to the next integer | `8 // 3 == 2` |

** | Exponent | Raising the first operand to the power of the second operand | `2 ** 3 == 8` |

While working as a researcher in distributed systems, Dr. Christian Mayer found his love for teaching computer science students.

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