Regex validate PIN code

ATM machines allow 4 or 6 digit PIN codes and PIN codes cannot contain anything but exactly 4 digits or exactly 6 digits.

If the function is passed a valid PIN string, return true, else return false.

Examples (Input --> Output)

"1234"   -->  true
"12345"  -->  false
"a234"   -->  false

Sample Tests

import codewars_test as test
from solution import validate_pin

@test.describe("Fixed Tests")
def fixed_tests():
    @test.it("should return False for pins with length other than 4 or 6")
    def basic_test_cases():    
        test.assert_equals(validate_pin("1"),False, "Wrong output for '1'")
        test.assert_equals(validate_pin("12"),False, "Wrong output for '12'")
        test.assert_equals(validate_pin("123"),False, "Wrong output for '123'")
        test.assert_equals(validate_pin("12345"),False, "Wrong output for '12345'")
        test.assert_equals(validate_pin("1234567"),False, "Wrong output for '1234567'")
        test.assert_equals(validate_pin("-1234"),False, "Wrong output for '-1234'")
        test.assert_equals(validate_pin("-12345"),False, "Wrong output for '-12345'")
        test.assert_equals(validate_pin("1.234"),False, "Wrong output for '1.234'")
        test.assert_equals(validate_pin("00000000"),False, "Wrong output for '00000000'")

    @test.it("should return False for pins which contain characters other than digits")
    def _():
        test.assert_equals(validate_pin("a234"),False, "Wrong output for 'a234'")
        test.assert_equals(validate_pin(".234"),False, "Wrong output for '.234'")

    @test.it("should return True for valid pins")
    def _():
        test.assert_equals(validate_pin("1234"),True, "Wrong output for '1234'")
        test.assert_equals(validate_pin("0000"),True, "Wrong output for '0000'")
        test.assert_equals(validate_pin("1111"),True, "Wrong output for '1111'")
        test.assert_equals(validate_pin("123456"),True, "Wrong output for '123456'")
        test.assert_equals(validate_pin("098765"),True, "Wrong output for '098765'")
        test.assert_equals(validate_pin("000000"),True, "Wrong output for '000000'")
        test.assert_equals(validate_pin("123456"),True, "Wrong output for '123456'")
        test.assert_equals(validate_pin("090909"),True, "Wrong output for '090909'")

Solution- ###Python

def validate_pin(pin):
    if(type(pin) != str or len(pin) not in [4, 6]):
        return(False)
    for c in pin:
        if c not in "0123456789":
            return(False)
    return(True)