I've written a simple script to help me better understand using classes. It generates a random character for a game. I defined the object and then call a function on that object that prints out the generated character. At the end of the printed block, there is an extraneous "None" that I'm not sure where it's coming from nor why it's being printed. Here's the sample output:
ted
Strength : 20
Dexterity : 17
Hit Points: 100
Aura : 100
Weapon :
Spell :
Item :
Element :
--------------------
None
In my code, the last line of player.stats()
is print "-" * 20
which is displayed right above "None". Here's the code that defines the object:
class Player(object):
def __init__(self, name):
self.name = name
self.strength = randint(15, 20)
self.dexterity = randint(15, 20)
self.hit_points = 100
self.aura = 100
self.weapon = " "
self.spell = " "
self.item = " "
self.element = " "
def stats(self):
print "\n"
print self.name
print "Strength : %d" % self.strength
print "Dexterity : %d" % self.dexterity
print "Hit Points: %d" % self.hit_points
print "Aura : %d" % self.aura
print "Weapon : %s" % self.weapon
print "Spell : %s" % self.spell
print "Item : %s" % self.item
print "Element : %s" % self.element
print "-" * 20
The object is then instanced using this:
name = raw_input("Name your character: ")
player = Player(name)
print player.stats()
The complete code can be read here at Pastebin if necessary.
print player.stats()
Is the culprit. player.stats() == None
You want just:
player.stats()
You'd do better to name your function player.printStats()
.
Another option would be to make it return a string:
def stats(self):
return '\n'.join([
self.name
"Strength : %d" % self.strength,
"Dexterity : %d" % self.dexterity,
"Hit Points: %d" % self.hit_points,
"Aura : %d" % self.aura,
"Weapon : %s" % self.weapon,
"Spell : %s" % self.spell,
"Item : %s" % self.item,
"Element : %s" % self.element,
"-" * 20
])
And then print player.stats()
would behave as expected
The stats()
method does not return anything. A function that doesn't return anything evaluates to None
. Which is what you print.
So, don't print the return value of the function. Just call it. Now, you should rename the function as printStats()
to make it clear what it does. And then just call it like this:
def printStats(self):
....
player = Player(name)
player.printStats()
Naming is a really important part of programming. A slightly poor choice of name often leads to confusion like this.
You print the return value of player.stats()
:
print player.stats()
but the .stats()
method does not have a return statement. The default return value of any function or method in python is None
, if no return statement has been given:
>>> def foo():
... pass
...
>>> print foo()
None
Either remove the print
before the method call, or have stats()
return a string to print instead of doing all the printing in the method.
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