first return works, the second doesn't
I'm doing the following exercise:
A number chain is created by continuously added the square of the
digits of a number to form a new number until it has been seen
before.For example:
44 → 32 → 13 → 10 → 1 → 1
85 → 89 → 145 → 42 → 20 → 4 → 16 → 37 → 58 → 89
Therefore any chain that arrives at 1 or 89 will become stuck in an
endless loop.
What is most amazing is that EVERY starting number will eventually
arrive at 1 or 89.
How many starting numbers below ten million will arrive at 89?
And my code just now is:
def start () :
start_range = range(4)
res = map(getDigits, start_range)
print(list(res))
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
getDigits(sumOfSquares)
else :
return check
def checkNum(num) :
if num == 0 or num == 1 :
print(type(num))
print(num)
return 0
elif num == 89 :
print(type(num))
print(num)
return 1
else :
return False
def toInt (char) :
return int(char)
def getSquareOfDigits (num) :
return num * num
start()
The output is
<class 'int'>
0
<class 'int'>
1
<class 'int'>
89
<class 'int'>
89
[0, 0, None, None]
And I don't understand why, if it goes correctly through the elif it doesn't return the '1' and add it correctly to the list.
python python-3.x
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
add a comment |
I'm doing the following exercise:
A number chain is created by continuously added the square of the
digits of a number to form a new number until it has been seen
before.For example:
44 → 32 → 13 → 10 → 1 → 1
85 → 89 → 145 → 42 → 20 → 4 → 16 → 37 → 58 → 89
Therefore any chain that arrives at 1 or 89 will become stuck in an
endless loop.
What is most amazing is that EVERY starting number will eventually
arrive at 1 or 89.
How many starting numbers below ten million will arrive at 89?
And my code just now is:
def start () :
start_range = range(4)
res = map(getDigits, start_range)
print(list(res))
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
getDigits(sumOfSquares)
else :
return check
def checkNum(num) :
if num == 0 or num == 1 :
print(type(num))
print(num)
return 0
elif num == 89 :
print(type(num))
print(num)
return 1
else :
return False
def toInt (char) :
return int(char)
def getSquareOfDigits (num) :
return num * num
start()
The output is
<class 'int'>
0
<class 'int'>
1
<class 'int'>
89
<class 'int'>
89
[0, 0, None, None]
And I don't understand why, if it goes correctly through the elif it doesn't return the '1' and add it correctly to the list.
python python-3.x
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
Can you clarify how your result is different from what you were expecting? As you only printtype(num)you always get<class 'int'>. Perhaps you wantedprint (type(check))ingetDigitsinstead? That will print the occasional<class 'bool'>.
– usr2564301
Nov 16 '18 at 10:05
add a comment |
I'm doing the following exercise:
A number chain is created by continuously added the square of the
digits of a number to form a new number until it has been seen
before.For example:
44 → 32 → 13 → 10 → 1 → 1
85 → 89 → 145 → 42 → 20 → 4 → 16 → 37 → 58 → 89
Therefore any chain that arrives at 1 or 89 will become stuck in an
endless loop.
What is most amazing is that EVERY starting number will eventually
arrive at 1 or 89.
How many starting numbers below ten million will arrive at 89?
And my code just now is:
def start () :
start_range = range(4)
res = map(getDigits, start_range)
print(list(res))
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
getDigits(sumOfSquares)
else :
return check
def checkNum(num) :
if num == 0 or num == 1 :
print(type(num))
print(num)
return 0
elif num == 89 :
print(type(num))
print(num)
return 1
else :
return False
def toInt (char) :
return int(char)
def getSquareOfDigits (num) :
return num * num
start()
The output is
<class 'int'>
0
<class 'int'>
1
<class 'int'>
89
<class 'int'>
89
[0, 0, None, None]
And I don't understand why, if it goes correctly through the elif it doesn't return the '1' and add it correctly to the list.
python python-3.x
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
I'm doing the following exercise:
A number chain is created by continuously added the square of the
digits of a number to form a new number until it has been seen
before.For example:
44 → 32 → 13 → 10 → 1 → 1
85 → 89 → 145 → 42 → 20 → 4 → 16 → 37 → 58 → 89
Therefore any chain that arrives at 1 or 89 will become stuck in an
endless loop.
What is most amazing is that EVERY starting number will eventually
arrive at 1 or 89.
How many starting numbers below ten million will arrive at 89?
And my code just now is:
def start () :
start_range = range(4)
res = map(getDigits, start_range)
print(list(res))
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
getDigits(sumOfSquares)
else :
return check
def checkNum(num) :
if num == 0 or num == 1 :
print(type(num))
print(num)
return 0
elif num == 89 :
print(type(num))
print(num)
return 1
else :
return False
def toInt (char) :
return int(char)
def getSquareOfDigits (num) :
return num * num
start()
The output is
<class 'int'>
0
<class 'int'>
1
<class 'int'>
89
<class 'int'>
89
[0, 0, None, None]
And I don't understand why, if it goes correctly through the elif it doesn't return the '1' and add it correctly to the list.
python python-3.x
python python-3.x
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
edited Nov 17 '18 at 22:15
mkrieger1
4,72722133
4,72722133
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
asked Nov 16 '18 at 9:15
J. Doe IIJ. Doe II
1
1
Can you clarify how your result is different from what you were expecting? As you only printtype(num)you always get<class 'int'>. Perhaps you wantedprint (type(check))ingetDigitsinstead? That will print the occasional<class 'bool'>.
– usr2564301
Nov 16 '18 at 10:05
add a comment |
Can you clarify how your result is different from what you were expecting? As you only printtype(num)you always get<class 'int'>. Perhaps you wantedprint (type(check))ingetDigitsinstead? That will print the occasional<class 'bool'>.
– usr2564301
Nov 16 '18 at 10:05
Can you clarify how your result is different from what you were expecting? As you only print
type(num) you always get <class 'int'>. Perhaps you wanted print (type(check)) in getDigits instead? That will print the occasional <class 'bool'>.– usr2564301
Nov 16 '18 at 10:05
Can you clarify how your result is different from what you were expecting? As you only print
type(num) you always get <class 'int'>. Perhaps you wanted print (type(check)) in getDigits instead? That will print the occasional <class 'bool'>.– usr2564301
Nov 16 '18 at 10:05
add a comment |
1 Answer
1
active
oldest
votes
In recursive functions you must have return values in your recursive call
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
---------> return getDigits(sumOfSquares)
else :
return check
add a comment |
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1 Answer
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1 Answer
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active
oldest
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oldest
votes
active
oldest
votes
In recursive functions you must have return values in your recursive call
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
---------> return getDigits(sumOfSquares)
else :
return check
add a comment |
In recursive functions you must have return values in your recursive call
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
---------> return getDigits(sumOfSquares)
else :
return check
add a comment |
In recursive functions you must have return values in your recursive call
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
---------> return getDigits(sumOfSquares)
else :
return check
In recursive functions you must have return values in your recursive call
def getDigits (num) :
check = checkNum(num)
if check is False :
strNum = str(num)
numList = map(toInt, strNum)
squareList = map(getSquareOfDigits, numList)
sumOfSquares = sum(squareList)
---------> return getDigits(sumOfSquares)
else :
return check
answered Nov 17 '18 at 20:25
user10608741
add a comment |
add a comment |
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Can you clarify how your result is different from what you were expecting? As you only print
type(num)you always get<class 'int'>. Perhaps you wantedprint (type(check))ingetDigitsinstead? That will print the occasional<class 'bool'>.– usr2564301
Nov 16 '18 at 10:05