None is printing

Question

def lucky_number(name):
  number = int(len(name) * 9)
  pr = "Hello " + name + ". Your lucky number is " + str(number)
  print(str(pr))

print(lucky_number("Kay"))
print(lucky_number("Cameron"))

output

Hello Kay. Your lucky number is 27
None
Hello Cameron. Your lucky number is 63
None

why iam geting none

Tip: You can skip int cast here `number = int(len(name) * 9)`, because `len(name)` returns an int. Same for `str(pr)`; pr is already a str. — santo, May 30 '20 at 07:51

David · Answer 1 · 2020-05-30T07:49:57.273

1

While every function might not have an explicit return it will have an implicit one, that is None, which incidentally is a normal Python object. Further, functions often return None explicitly.

So calling the function from within the print, without a return Value so None is returned and being printed.

To avoid this issue you should return a desired value from function.

edited May 30 '20 at 07:49

answered May 30 '20 at 07:47

David

8,113
2
17
36

So putting a `return` at the end of the function, would solve the problem? – Charalamm May 30 '20 at 07:49
@Phineas putting a return with some sort of desired value, yes. – David May 30 '20 at 07:50

score 0 · Answer 2 · edited May 30 '20 at 08:10

Because you haven't return anything. If code is like this:

def lucky_number(name):
  number = int(len(name) * 9)
  pr = "Hello " + name + ". Your lucky number is " + str(number)
  print(str(pr))
  return "OK"

print(lucky_number("Kay"))
print(lucky_number("Cameron"))

Output:

Hello Kay. Your lucky number is 27
OK
Hello Cameron. Your lucky number is 63
OK

Calling the function in print(), prints the output of the function, in this case OK. But the string that you wanted to print is printed by the function itself, not because of the print that is calling the function.

So code like this:

def lucky_number(name):
  number = int(len(name) * 9)
  pr = "Hello " + name + ". Your lucky number is " + str(number)
  print(str(pr))

lucky_number("Kay")
lucky_number("Cameron")

Output:

Hello Kay. Your lucky number is 27
Hello Cameron. Your lucky number is 63

score 0 · Answer 3 · answered May 30 '20 at 07:49

here you are printing the output:

print(str(pr))

and here you are printing none:

print(lucky_number("Kay"))

why are you printing in calling method? just call it simply, not printing.

or instead of print(str(pr)) use return str(pr) and print the output while calling the method.

score 0 · Answer 4 · answered May 30 '20 at 07:52

0

try this

def lucky_number(name):
  number = int(len(name) * 9)
  pr = "Hello " + name + ". Your lucky number is " + str(number)
  return pr

print(lucky_number("Kay"))
print(lucky_number("Cameron"))

answered May 30 '20 at 07:52

Ryhan Ahmed

63
6

score 0 · Answer 5 · answered May 30 '20 at 07:54

The function returns none after printing the statement. You can modify the code as below to use the return in your favor.

def lucky_number(name):
    number = int(len(name) * 9)
    pr = 'Hello ' + name + '. Your lucky number is ' + str(number)
    return(str(pr))

print(lucky_number('kay'))
print(lucky_number('Cameron'))

Or, you can just call the function and skip the print statement while calling to get rid of this.

def lucky_number(name):
    number = int(len(name) * 9)
    pr = 'Hello ' + name + '. Your lucky number is ' + str(number)
    print(str(pr))

lucky_number('kay')
lucky_number('Cameron')

None is printing

5 Answers5