I am learning to create functions. The whole program basically prints only the even digits of a number, but I need to create a function that, in case the number has no even digits, will print that it doesn't have any, but I have no idea on how to make the condition. Thanks in advance.

So far this is the code without the function I need:

def imprimirPares (num):
    while num != 0:
        resultado = 0
        i = 1
        digito = num % 10
        if digito % 2 == 0:
            resultado  = digito * i
            i *= 10
        num // 10
    return resultado

def ingresarEyS (num):
    print ("Nuevo numero con los valores pares de la cifra: ")
    num = ()
    print ("El nuevo numero es ",imprimirPares(num),".")

CodePudding user response：

Using your already existing function this is fairly easy. One error you have made is that you do not assign the result of num // 10 to num though.

def has_even_digit(num):
    while num != 0:
        result = 0
        i = 1
        digit = num % 10
        if digit % 2 == 0:
            # even digit found
            return True
        else:
            result  = digit * i
            i *= 10
            num = num // 10
    return False


print(has_even_digit(45))
print(has_even_digit(13))
print(has_even_digit(1579315))
print(has_even_digit(780278452))

Expected output:

True
False
False
True

CodePudding user response：

So I assume you are given a number, for example "2345", and you are supposed to print "2, 4".

1. Convert the number to string:
2. Create empty list to append even digits and Iterate:

def evenDigits(num):
  num = str(num)
  evenNumbers = [] //empty list to store even numbers
  for digit in num:
    if digit % 2 == 0: //check if even digit
      evenNumbers.append(digit)

return evenNumbers //returns list with even numbers

num = input("Give me a number!")
result = evenDigits(num)
print(*result, sep = ", ") //will print all even digits on same line.

CodePudding user response：

You could create two separate functions for obtaining the digits and then checking if any digit is divisible by two.

from numbers import Number
from prettytable import PrettyTable

def get_digits(num: Number) -> list[int]:
    return [int(d) for d in str(num) if d.isdigit()]

def contains_even(digits: list[int]) -> bool:
    return any(x % 2 == 0 for x in digits)

def main() -> None:
    t = PrettyTable(['x', 'digits', 'contains_even'])
    t.align = "l"
    for x in [11, -1230, -193.23, complex(5.4, 4.5), 23, 7.135, 0.354]:
        d = get_digits(x)
        t.add_row([x, d, contains_even(d)])
    print(t)

if __name__ == '__main__':
    main()

Output:

 ------------ ----------------- --------------- 
| x          | digits          | contains_even |
 ------------ ----------------- --------------- 
| 11         | [1, 1]          | False         |
| -1230      | [1, 2, 3, 0]    | True          |
| -193.23    | [1, 9, 3, 2, 3] | True          |
| (5.4 4.5j) | [5, 4, 4, 5]    | True          |
| 23         | [2, 3]          | True          |
| 0.354      | [0, 3, 5, 4]    | True          |
 ------------ ----------------- ---------------