# Python complex() Function with Examples

The complex() built-in python function is used to convert string into complex number or when a real and imaginary parts (i.e., 3+7j) are provided....

In this tutorial we will discuss about the complex() function in python programming language with the help of examples.

## Python complex() function

The built-in python function is used to convert string into complex number or when a real and imaginary parts (i.e., 3+7j) are provided it returns a complex number. The string passed to complex() function should be in form.

### Syntax

`complex([real[, imag]])  `

## Parameters of complex() function in python

The complex() function in python takes two parameters;

- numeric type real part. 0 is to be the default value, if real part is omitted.

- numeric type imaginary part. 0 is to be the default value, if imag part is omitted.

## Return value of Python complex() function

In python, when a real and imaginary parts are provided function returns a complex number. It is also used to convert string into complex number. The string passed to complex() function should be in form.

Note - If the passed string is not a valid complex number then it will raise a [ValueError] exception.

#### Example 1: Creating a complex number in Python

`x = complex(7, -2)print(x)x = complex(5)print(x)x = complex()print(x)x = complex('6-8j')print(x)`

Output

```(7-2j)
(5+0j)
0j
(6-8j)```

#### Example 2: Creating complex Number Without Using Python complex() function

`a = 5+8jprint('a =',a)print('Type of a is',type(a))b = -3jprint('b =',b)print('Type of b is',type(a))c = 0jprint('c =',c)print('Type of c is',type(c))`

Output

```a = (5+8j)
Type of a is <class 'complex'>
b = (-0-3j)
Type of b is <class 'complex'>
c = 0j
Type of c is <class 'complex'>```

#### Example 3: The strings to be used as parameters in python complex() Function

`x = complex('5') y = complex('1.7')  print(x)  print(y)`

Output

```(5+0j)
(1.7+0j)```

#### Example 4: The Python complex() function accepts only one string parameter as the input

`x = complex('7','4')print(x) `

Output

`TypeError: complex() can't take the second arg if first is a string`