Python3 is completely free on Paiza, so I summarized it.
lesson.py
#Both print and text are functions
#Functions can perform processing using values
#In the case of the following print whose value is called "argument""hello world"
#The result processed in the function is returned as a "return value" and can be assigned to a variable etc.
print("hello world")
#If it is input, the character string of the value input from the keyboard becomes the "return value" and can be assigned to the variable.
text=input()
Function function </ strong>
・ Divide and organize long codes → improve visibility
・ You can name the code
・ You can call the code as many times as you like → You can reuse it
・ You can combine codes
lesson.py
#Create a function
#def=definition
def say_hello():
print("hello world")
say_hello()
text.txt
hello world
lesson.py
#Create a function
#You can create your own function
#def=definition
def say_hello():
print("hello world")
say_hello()
say_hello()
text.txt
hello world
hello world
lesson.py
def say_hello():
print("hello paiza")
#Write a function call below this
say_hello()
hello paiza
lesson.py
def say_hello():
#Describe the processing in the function below this
print("hello python")
say_hello()
lesson.py
Last review
def say_hello():
print("hello world")
say_hello()
def sum():
print(10+20)
sum()
#Always 10+Having a function to calculate 20 doesn't help much
#If the function call has an argument, the function definition(x)Passed to a variable
#variable(x)Create a function that changes by changing
def sum(x):
#def sum(variable):
print( x + 20)
sum(30)
#Function with two arguments
print(x + y)
sum(3,2)
#Add arguments and return value
def sum(x,y):
#Return to function definition and set
return x + y
#In the nu1 variable(return x +y is)To be stored
num1=sum(3,4)
print(num1)
num1=sum(300,400)
print(num1)
lesson.py
def multiply(x, y):
return x * y
#Write a function call below this
ans =multiply(3,4)
print(ans)
lesson.py
#Let's create a multiplication function
def multiply(x, y):
#Describe the process below this
return x*y
print(multiply(3, 4))
print(multiply(5, 7))
print(multiply(12, 34))
lesson.py
#Let's create a multiplication table
def multiply(x, y):
return x * y
for step in range(1,10):
for num in range(1, 10):
print(multiply(step, num), end="")
if num < 9:
print(", ", end="")
print("")
lesson.py
'''
#review
def sum(x,y):
return x + y
num = sum (3,2)
print(num)
'''
#I used to use variables when calling functions
def sum(x,y):
return x + y
a=10
b=30
num sum(a,b)
print(num)
#It's okay to write weird before the definition
a=10
b=20
def sum(x,y):
return x + y
num sum(a,b)
print(num)
lesson.py
#Even if I decide a lot of variables and make a mistake and it seems to be duplicated, it seems to work normally,
#The effective range of the variable is fixed and it is called "scope".
a=10
b=20
def sum(x,y):
a=3
print("hello" + str(a))
return x + y
num = sum(a,b)
print(num)
hello3
30
#Because the scope is separated inside and outside
#The value is output without any problem
#The outer a variable and the inner a variable are treated as different things
lesson.py
There are local variables and global variables
Local variables ... with scope
Global variables ... can be used anywhere
#message is a global variable
message="paiza"
a=10
b=20
def sum(x,y):
a=3
#Be careful when changing global variables
#Global variables are only allowed to be referenced from within the function,
#Assignments and changes are not allowed as they are
#Use global message to change
#global message
#message += "paiza"
print("hello" + str(a))
return x + y
num = sum(a,b)
print(num)
#Global variables can be used in common both inside and outside function definitions
#Even if you assign a value to a variable with the same name in the function definition, it automatically becomes another local variable.
#Does not affect global variables
print(message+ " " + str(a))
Finding mistakes
lesson.py
msg = "hello"
def say_hello():
global msg
msg += " "
msg += "paiza"
print(msg)
say_hello()
lesson.py
#RPG attack scene
import random
def attack(enemy):
print("The hero"+ enemy + "Attacked")
enemies = ["Slime","monster","Dragon"]
for enemy in enemies:
#print("The hero"+ enemy + "Attacked")
attack(enemy)
#The scope of the def enemy variable and the for enemy variable are different.
lesson.py
#Make a critical hit according to a random value
import random
def attack(enemy):
print("The hero"+ enemy + "Attacked")
hit =random.randint(1,10)
#Normal damage when 6 or less, critical hits otherwise
if hit <6:
print(enemy + "To" +str(hit) + "Damaged")
else:
print("critical hit!" + enemy+ "Inflicted 100 damage on!")
enemies = ["Slime","monster","Dragon"]
for enemy in enemies:
#print("The hero"+ enemy + "Attacked")
attack(enemy)
#The scope of the def enemy variable and the for enemy variable are different.
lesson.py
def attack(person):
print(person + "Attacked the slime")
def output_ememy_hp(enemy_hp):
print("Enemy HP remains" + str(enemy_hp) + "is")
enemy_hp = int(input())
team = {"Brave" : 200, "Warrior" : 150, "Wizard" : 100}
for person, power in team.items():
attack(person)
#Below, write the code to reduce the enemy's health
enemy_hp -= power
output_ememy_hp(enemy_hp)
output
lesson.py
#Default value of argument
#Default value that can be used when the argument is omitted
def introduce(name):
print("I"+name+"is")
introduce("Brave")
'''
output
I am a brave man
lesson.py
#Get arguments only when you have a special role
#Use it and automatically become a "villager" when there are no arguments
#You can do that with the default values
#You can specify the default value of the argument,
#If you call a function with no arguments, its default value is used.
#Pass the villager as an argument
def introduce(name = "Villager"):
print("I" + name+ "is.")
introduce("Brave")
introduce()
output
I am a brave man
I am a villager
lesson.py
#If you use the default value, it will be automatically omitted if you omit the argument.
#Initial value can be specified
#However, there is a function that sets the default value as an argument,
#If you want to add a new argument there, be careful about the position
def introduce(name = "Villager",greeting):
print("I" + name+ "is."+greeting)
introduce("Brave","Hello")
introduce("Hello")
#Doing the above will result in an error
#The argument for which you want to set the default value must be written after the argument without the default value
#So swap greeting and name
def introduce(greeting,name = "Villager"):
print("I" + name+ "is."+greeting)
introduce("Brave","Hello")
introduce("Hello")
I am a Hello. Brave
I am a villager Hello
lesson.py
#Variadic argument
#Receive arguments, but use when you don't know how many arguments
#Fix the content of the greeting as a trial so that multiple people can greet
#Function argument from name*(asterisk)Change to names and use the default value"Villager"Delete"
def introduce(greeting,*names):
#Repeat the process
for name in names:
print("I" + name+ "is."+greeting)
#(Hello → greeting,Hero, villager, soldier →*names)Was put in
introduce("Hello","Brave","Villager","Soldier")
lesson.py
#Variadic argument-dictionary
＃**Change to people
def introduce(**peple):
#Iterate over name, greeting,inpep;e.imes()change to
for name,greeting in peple.items():
print("I" + name+ "is."+greeting)
print(peple)
#(Hello → greeting,Hero, villager, soldier →*names)Was put in
introduce(hero="Nice to meet you",villager="Hello",soldier ="I look forward to working with you.")
output
I am here Nice to meet you
I'm a villager Hello
I'm a soldier I look forward to working with you.
{'here': 'Nice to meet you', 'villager': 'Hello', 'soldier': 'I look forward to working with you.'}
lesson.py
def say_hello(target = "paiza"):
print("hello " + target)
#Write a function call below this
say_hello()
lesson.py
#enemies*Enemies
def battle(*enemies):
for enemy in enemies:
print("The warrior" + enemy + "Fought with")
battle("Slime", "monster", "Dragon")
lesson.py
#Keyword arguments
#Function if the argument is omitted
#"Hello" in greeting variable,"World" is in the target variable
#Output
def say_hello(greeting = "hello",target="world"):
print(greeting + " " + target)
#hello world
say_hello()
#Hello greeting, state that contains everyone in taeget
say_hello("Hello","everyone")
#If you use the default value for the argument, you can omit the argument when calling
#It is in the greeting variable and the target variable is omitted
#Therefore, it is output as good morning world.
say_hello("good morning")
#There is a "keyword argument" that labels the arguments
#Note that it is not an assignment because it is labeled, it is temporary
say_hello(greeting="Hello",target="everyone")
#You can also change the order of the arguments
say_hello(target="Cat teacher",greeting="Good morning")
#If the "keyword variable" has a default value, its argument can be omitted.
say_hello(target="Cat teacher")
say_hello(greeting="Good morning")
output
hello world
Hello everyone
good morning world
Hello everyone
Good morning cat teacher
hello cat teacher
Good morning world
lesson.py
Expected output value
I am a villager
def introduce(name = "I", role = "Villager"):
print(name + role + "is")
#Below this, describe the necessary processing
introduce()
lesson.py
I am a warrior
def introduce(name = "I", role = "Villager"):
print(name + role + "is")
#Below this, describe the necessary processing
introduce(role="Warrior")
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