Python complex() Function – Tutorial with Examples

The complex() function in Python is used to convert a number or string representation of a number into a complex number. The function can take a real number, an imaginary number, or a string representation of a complex number, and return the corresponding complex number object.

Syntax

```complex(real, imag=0.0)
```

Parameters

• real : This is the real part of the complex number. It can be an integer, float, or a string representation of a number.
• imag : This is the imaginary part of the complex number. It must be a float, and the default value is 0.0

Return Value

The complex() function returns a complex number object, which can be used in mathematical operations that involve complex numbers.

Examples

Example 1: Creating a complex number from real and imaginary parts

```# create a complex number using real and imaginary parts
c = complex(2, 3)
print(c)
```

Output.

```(2+3j)
```

Example 2: Creating a complex number from a string representation

```# create a complex number using a string representation
c = complex("2+3j")
print(c)
```

Output.

```(2+3j)
```

Example 3: Using the real parameter only

```# create a complex number using only the real part
c = complex(2)
print(c)
```

Output.

```(2+0j)
```

Use Cases

The complex() function is useful in mathematical operations that involve complex numbers, such as finding roots of polynomials, solving systems of linear equations, and more. The function makes it easy to create complex numbers from real or string representations and makes it possible to perform mathematical operations on them.

Additionally, the complex() function can be used to parse a string representation of a complex number, making it easier to work with data that is represented in this format. This is especially useful when dealing with data from external sources, such as text files or API responses, that contain complex numbers in string form.

In summary, the complex() function is a crucial tool for working with complex numbers in Python, and its ability to convert real numbers, imaginary numbers, and string representations into complex numbers makes it a versatile and indispensable tool for a wide range of mathematical applications.