expected two blank lines pep8 warning in python

Here is the link to the documentation: PEP8 Style Guide for Python
You should add two spaces between the functions, as shown below:

import cmath


def sqrt():
    try:
        num = int(input("Enter the number : "))
        if num >= 0:
            main(num)
        else:
            complex_num(num)
    except:
        print("OOPS..!!Something went wrong, try again")
        sqrt()
    return


def main(num):
    square_root = num ** (1 / 2)
    print("The square Root of ", num, " is ", square_root)
    return


def complex_num(num):
    ans = cmath.sqrt(num)
    print("The Square root if ", num, " is ", ans)
    return


sqrt()

import cmath


def sqrt():
    try:
        num = int(input("Enter the number : "))
        if num >= 0:
            main(num)
        else:
            complex_num(num)
    except:
        print("OOPS..!!Something went wrong, try again")
        sqrt()
    return


def main(num):
    square_root = num**(1/2)
    print("The square Root of ", num, " is ", square_root)
    return


def complex_num(num):
    ans = cmath.sqrt(num)
    print("The Square root if ", num, " is ", ans)
    return

sqrt()

The previous will fix your PEP8 problems. After your import you need to have 2 new lines before starting your code. Also, between each def foo() you need to have 2 as well.

In your case you had 0 after import, and you had 1 newline between each function. Part of PEP8 you need to have a newline after the end of your code. Unfortunately I don't know how to show it when I paste your code in here.

Pay attention to the naming, it's part of PEP8 as well. I changed complex to complex_num to prevent confusion with builtin complex.

In the end, they're only warning, they can be ignored if needed.

You need to give two blank lines between meaningful code blocks.

These include (for example):

• The import block
• Each function