How to Check Complex Numbers in Python

Complex numbers are an essential component in several areas of mathematics and physics. A complex number is a number in the form of a+bj where ‘a’ and ‘b’ are floats and ‘j’ represents the square root of -1. In Python, complex numbers can be defined and manipulated using various built-in methods.

Checking the Type of a Number

To determine whether a number is complex in Python, we use the type() function. If the output of the type() function is <class ‘complex’> then the number is complex.

See the example below:

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num = 5+3j
print(type(num))

The Output:

<class 'complex'>

Using isinstance() to Check for a Complex Number

The isinstance() function can be used to check if the given number is complex or not. It returns True if the number is complex; otherwise, it returns False.

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num = 5+3j
print(isinstance(num, complex))

The Output:

True

Creating Complex Numbers

There are two ways to create a complex number in Python: either by direct assignment to a variable or by using the built-in complex() function.

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# Direct assignment
num1 = 5 + 3j
 
# Using complex() function
num2 = complex(5, 3)
 
print(num1)
print(num2)

The Output:

(5+3j)
(5+3j)

Full Code

In this tutorial, we have learned how to check and create complex numbers in Python. Here is the full code we used:

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# Checking the type
num = 5+3j
print(type(num))
 
# Using isinstance() function
num = 5+3j
print(isinstance(num, complex))
 
# Creating complex numbers
num1 = 5 + 3j
num2 = complex(5, 3)
 
print(num1)
print(num2)

Conclusion

In this tutorial, you learned how to check complex numbers in Python. You also explored how to create complex numbers using both direct assignment and the built-in complex() function.

With this basic understanding, you can now effectively use and manipulate complex numbers in your Python programs.