Screen Link:
My Code:
First case:
def welcome(a_string):
# return a_string+ 50
print('Wellcome to ' + a_string + ' !')
dq = 'dataquest'
py = 'Python'
jn= 'Jupyter Notebook'
print(welcome(dq))
What I expected to happen:
I expected to see the only line: Wellcome to dataquest !
What actually happened:
Actually, I see
Wellcome to dataquest !
None
Can any body please explain why I see “None” ?
Second case:
Another basic question: why the code is working even if I haven’t mentioned the ‘return’ ?
Say I wanted to sum a_string+ 50 if I don’t put return a_string+ 50 it is showing the error. In that case I called welcome(40).
If I do return a_string+ 50
and print(welcome(40))
it is giving me 90.
So why it is working for 1 st case not for the 2 nd case. I expected same answer.
1 Like
@mondalsou: In the first case you are calling the function with welcome(dq). Then you attempt to print it internally in the function, resulting in string Wellcome to dataquest ! .
Thereafter the function automatically returns with the default value of None (similar to null in other programming languages and signifying the absence of a value). The value returned to the function is then passed on to the built-in function print(), which regurgitates None.
So the output is as follows:
Wellcome to dataquest !
None
By default python unlike other languages has sort of a “fallback” if you don’t specify it and the default return value is None.
There is no error in this case… if you would kindly elaborate as your description is not very clear. A code snippet would be helpful.
As shown above, None is returned.
2 Likes
I got your point. Now, I understand what I was doing wrong:
I found that both are giving the same results:-
Thanks
2 Likes
