# Python complex() Function

• Last Updated : 26 Jul, 2022

Python complex() function returns a complex number ( real + imaginary) example (5+2j) when real and imaginary parts are passed, or it also converts a string to a complex number.

## Python complex() Function Syntax

Syntax: complex ([real[, imaginary]])

• real [optional]: numeric type (including complex). It defaults to zero.
• imaginary [optional]: numeric type (including complex) .It defaults to zero.

Return: Returns a complex number in the form of (real + imaginary) example (5+2j)

Note: If the first parameter that passed is a string then the second parameter shouldn’t be passed else will raise TypeError. The string must not contain whitespace around + or – operator else it will raise ValueError in Python.

## Python3

 `print``(``complex``(``1``, ``2``))`

Output:

`(1+2j)`

### Example 1:

Using complex() with Integer and Float type parameters.

## Python3

 `# numeric type``# nothing is passed``z ``=` `complex``()``print``(``"complex() with no parameters:"``, z)`  `# integer type``# passing first parameter only``complex_num1 ``=` `complex``(``5``)``print``(``"Int: first parameter only"``, complex_num1)` `# passing both parameters``complex_num2 ``=` `complex``(``7``, ``2``)``print``(``"Int: both parameters"``, complex_num2)` `# float type``# passing first parameter only``complex_num3 ``=` `complex``(``3.6``)``print``(``"Float: first parameter only"``, complex_num3)` `# passing both parameters``complex_num4 ``=` `complex``(``3.6``, ``8.1``)``print``(``"Float: both parameters"``, complex_num4)``print``()` `# type``print``(``type``(complex_num1))`

Output

```Nothing is passed 0j
Int: first parameter only (5+0j)
Int: both parameters (7+2j)
Float: first parameter only (3.6+0j)
Float: both parameters (3.6+8.1j)

<class 'complex'>```

### Example 2:

Using complex() with string type parameters of the numeric form.

## Python3

 `# string``# only first parameter is to be passed``z1 ``=` `complex``(``"7"``)``print``(z1)` `print``()``z2 ``=` `complex``(``"2"``, ``"3"``)` `# This will raise TypeError"``print``(z2)`

Output:

### Example 3:

Using complex() with string type parameters of Complex Number form.

## Python3

 `# string``# only first parameter is passed``z1 ``=` `complex``(``"7+17j"``)``print``(z1)` `print``()``z2 ``=` `complex``(``"7 + 17j"``)` `# This will raise Valueerror``# due to spaces around operator``print``(z2)`

Output:

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