Why the function is not returning the value but printing the same?

Question

See this function:-

def beej(v):
    v = sum(map(int, list(str(v))))
    if len(str(v)) <=1:
        print("printed: {}".format(v))  
        return v
    beej(v)

#outputs
>>> beej(23)
printed: 5
5                # returned
>>> beej(4221)
printed: 9
9                # returned
>>> beej(422199)
printed: 9       #no returned value
>>> beej(999)
printed: 9       #no returned value

So; its simply working for some values; and not for others. I'd like to know the reason behind this; and how to find such hidden bugs.

DeepSpace · Accepted Answer · 2019-03-03T14:25:37.920

1

You are missing a return statement in the recursive call:

def beej(v):
    v = sum(map(int, list(str(v))))
    if len(str(v)) <= 1:
        print("printed: {}".format(v))  
        return v
    return beej(v)

Your current code will only return v if the first call to beej (ie no recursive calls) produces a single-digit sum.

edited Mar 03 '19 at 14:25

answered Mar 03 '19 at 14:15

DeepSpace

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then why for some values, it does return the value? – Vicrobot Mar 03 '19 at 14:17
1

@Vicrobot Take a moment to think about it while considering the amount of the digits of the sum in cases where it returns compared to when it does not – DeepSpace Mar 03 '19 at 14:20
Thanks ! Got that. – Vicrobot Mar 03 '19 at 14:25

Why the function is not returning the value but printing the same?

1 Answers1