Python complex() Function

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The Python complex() function is used to create a complex number by combining a real part and an imaginary part.

The real part of a complex number represents the component that lies on the standard number line (the horizontal axis). It is a regular real number and can be positive, negative, or zero. In mathematical notation, if "z" is a complex number, the real part is denoted as "Re(z)".

The imaginary part of a complex number represents the component that lies on the imaginary axis (the vertical axis). It is a multiple of the imaginary unit "i" (or j in Python), where "i" is defined as the square root of "-1". In mathematical notation, if "z" is a complex number, the imaginary part is denoted as "Im(z)".

Syntax

Following is the syntax of Python complex() function −

complex(real [,imag])

Parameters

This function takes two optional parameters as shown below −

• real − It represents the real part of the complex number. If not provided, it defaults to 0.

• imag (optional) − It represents the imaginary part of the complex number. If not provided, it defaults to 0.

Return Value

This function returns a complex number based on the provided real and imaginary parts or a string representing a complex number.

Example 1

In the following example, we are using the complex() function to create a complex number with a real part of "2" and an imaginary part of "3" −

real = 2
imaginary = 3
result = complex(real, imaginary)
print('The complex value obtained is:',result)

Output

Following is the output of the above code −

The complex value obtained is: (2+3j)

Example 2

If we do not pass an imaginary part to the complex() function, its default value is set to 0.

Here, we are using the complex() function with only the real part "4" −

real = 4
result = complex(real)
print('The complex value obtained is:',result)

Output

Output of the above code is as follows −

The complex value obtained is: (4+0j)

Example 3

If we do not pass a real part to the complex() function, its default value is set to 0. Here, we are using the complex() function with only the imaginary part "7" −

imaginary = 7
result = complex(imag=imaginary)
print('The complex value obtained is:',result)

Output

The result obtained is as shown below −

The complex value obtained is: (7+0j)

Example 4

In here, we are using the complex() function without providing any real or imaginary parts. As a result, it defaults to 0j, representing a complex number with both real and imaginary parts equal to 0 −

result = complex()
print('The complex value obtained is:',result)

Output

Following is the output of the above code −

The complex value obtained is: 0j

Example 5

In the example below, the complex() function parses the string "2+4j" and creates the corresponding complex number (2+4j) −

result = complex("2+4j")
print('The complex value obtained is:',result)

Output

The result produced is as follows −

The complex value obtained is: (2+4j)