function without printing none - python-3.x

Question

for some reason I'm printing two Nones, can someone explain how to avoid that?
class Wizard():
def __init__(self,name, gender,power):
self.name = name
self.gender = gender
self.power = power
def fire(self):
print('My power is the fire')
def wind(self):
print ('My power is the wind')
def power_wizard(self):
if power == 1:
print(Wizard.fire(self))
else:
a=print(Wizard.wind(self))
# Create player
name = input('Enter your wizard name: ')
gender = input ('Enter the gender: ')
power = int(input ('Choose your power 1) Fire and 2) Wind:(only numbers)'))
player1 = Wizard(name,gender,power)
print(player1.name)
print(power_wizard(power))
print (The question is how can I not print None or why am I printing None)
My power is the fire
None
None
And also why are 2 None where are the coming from, because when de function wizard_power there only to results.

Answer 1

why am I printing None
When you execute print(power_wizard(power)), the following happens:
the power_wizard() function is called.
in that power_wizard() function, you call the Wizard.fire() or Wizard.wind() methods...
in both methods, you print('My power is...')...
...but you don't return any result.
in the power_wizard() function, you print the result of the Wizard.fire() or Wizard.wind() methods but, as those methods returns nothing, None is printed a first time.
the power_wizard() function returns no results either...
...thus, the outermost print(power_wizard(power)) prints a second None.
That said, your Wizard class and power_wizard() function are a bit tangled...
You could easily remove the Wizard.fire() and Wizard.wind() methods and the power_wizard() function and have:
class Wizard():
def __init__(self, name, gender, power):
self.name = name
self.gender = gender
self.power = power
player1 = Wizard("Gandalf", "male", "fire")
player2 = Wizard("Hermione", "female", "wind")
player3 = Wizard("Draco", "male", "invisibility")
for p in (player1, player2, player3):
print("My name is %s and I have %s power" % (p.name, p.power))
# My name is Gandalf and I have fire power
# My name is Hermione and I have wind power
# My name is Draco and I have invisibility power
If you want to restrict the list of Wizard powers:
class Wizard():
powers = ("fire", "wind") # this is a _class variable_ defining
# all powers available to Wizards
def __init__(self, name, gender, power):
self.name = name
self.gender = gender
if power in Wizard.powers:
self.power = power
else:
raise ValueError("%s is not a Wizard power." % (power))
player3 = Wizard("Draco", "male", "invisibility")
# ValueError: invisibility is not a Wizard power.
If you want to let wizards describe themselves:
class Wizard():
...
def __init__(self, name, gender, power):
...
def __repr__(self):
return "<% is a %s with %s power>" % (
self.name, self.__class__.__name__, self.power)
for p in (player1, player2):
print(p)
# <Gandalf is a Wizard with fire power>
# <Hermione is a Wizard with wind power>
Then, if you want to make a wizard interactively:
def make_wizard():
while True:
name = input("Enter your wizard name: ")
if name:
break
gender = input("Enter its gender: ")
choices = ", ".join(Wizard.powers)
while True:
power = input("Enter its power (%s): " % (choices))
if power in Wizard.powers:
break
return Wizard(name, gender, power)
player1 = make_wizard()
print(player1)
# Enter your wizard name:
# Enter your wizard name: Gandalf
# Enter its gender: male
# Enter its power (fire, wind): invisibility
# Enter its power (fire, wind): fire
#
# <Gandalf is a Wizard with fire power>
If you want powers to be numbered choices:
def make_wizard():
...
choices = ", ".join("%i: %s" % (i, name)
for i, name
in enumerate(Wizard.powers, start=1))
while True:
try:
choice = int(input("Enter its power (%s): " % (choices)))
# will raise ValueError if choice is not a int
power = Wizard.powers[choice-1]
# will raise IndexError if choice-1 is not
# in Wizard.powers range
except ValueError, IndexError:
continue
else:
break
return Wizard(name, gender, power)
player1 = make_wizard()
print(player1)
# Enter your wizard name:
# Enter your wizard name: Gandalf
# Enter its gender: male
# Enter its power (1: fire, 2: wind): invisibility
# Enter its power (1: fire, 2: wind): 3
# Enter its power (1: fire, 2: wind): 1
#
# <Gandalf is a Wizard with fire power>
(that was fun... ;-)

Answer 2

You can only run the print statement if its return is not None like this. Its a bandaid fix.
if player1.name is not None: print(player1.name)