Python built-in Method - complex()

The complex() method is a built-in function in Python that returns a complex number from a real and an imaginary component.

Here is the syntax for complex() method:

complex([real[, imag]])

where:

• real: a numeric value that represents the real part of the complex number. If real is not provided, it defaults to 0.
• imag: a numeric value that represents the imaginary part of the complex number. If imag is not provided, it defaults to 0.

Both real and imag can be integer or float values, or they can be represented as a string. If a string is used, it must contain a numeric value, optionally followed by the letter 'j' to indicate that the value is imaginary.

Here are some examples of how to use complex():

# create a complex number with real and imaginary components
z1 = complex(2, 3)
print(z1)   # (2+3j)

# create a complex number with only a real component
z2 = complex(4)
print(z2)   # (4+0j)

# create a complex number with only an imaginary component
z3 = complex('3j')
print(z3)   # 3j

# create a complex number from a string with both real and imaginary components
z4 = complex('4+5j')
print(z4)   # (4+5j)

In the first example, z1 is a complex number with real component 2 and imaginary component 3. In the second example, z2 is a complex number with real component 4 and imaginary component 0. In the third example, z3 is a complex number with real component 0 and imaginary component 3. In the fourth example, z4 is a complex number with real component 4 and imaginary component 5.

The complex() method is useful for performing mathematical operations that involve complex numbers, such as signal processing, control systems, and physics.