Getting started with Python programming to Practice-notes (Chapter 8)

The 8th chapter mainly exercises various functions, the contents are as follows

To define a simple function

Passing information to a function

What is a formal parameter

What is an argument

Position parameters

Calling functions multiple times

Keyword arguments

Default value parameter

Returned value return

Let the parameters be programmed with optional

Back to Dictionary

Using functions and while loops together

Delivery List

To modify a list in a function

Pass any number of arguments

Pass any number of parameters and cycle through the print

Use positional parameters together with any number of arguments

Use any number of keyword arguments

Import the entire module

Import a specific function

Assigning an alias to a function using as

Assigning an alias to a module using as

Import all functions in a module

To define a simple function

Directly call the function, you can print

--------------------------

Def greet_user ():
Print ("hello!")
Greet_user ()

---------------------------

Hello!

Passing information to a function

Username is just a formal parameter

------------------------------------------------------

def greet_user (username):
Print ("Hello," + username.title () + "!")
Greet_user (' Zhao ')

------------------------------------------------------

Hello, zhao!.

What is a formal parameter?

Take the code above as an example. Username is the formal parameter, it only represents greet_user this function needs to pass a parameter

It doesn't matter if it's called username or Nameuser.

What arguments?

Take the code above as an example. ' Zhao ' is an argument, and a summary is a real parameter to get the code to execute.

bit Place Arguments

The order of positional arguments is specified in the function brackets

Input parameters must be operated according to formal parameter hints

In short, the order of positional arguments is important.

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def describe_pet (Animal_type, Pet_name):
Print ("\ni has a" + Animal_type + ".")
Print ("My" + Animal_type + "s name is" + pet_name.title () + ".")
Describe_pet (' Hamster ', ' Harry ')

-------------------------------------------------------------------------------------------

I have a hamster.
My Hamster ' s name is Harry.

Calling functions multiple times

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def describe_pet (Animal_type, Pet_name):
Print ("\ni has a" + Animal_type + ".")
Print ("My" + Animal_type + "s name is" + pet_name.title () + ".")

Describe_pet (' Hamster ', ' Harry ')
Describe_pet (' Dog ', ' Willie ')

------------------------------------------------------------------------------------------

I have a hamster.
My Hamster ' s name is Harry.

I have a dog.
My Dog ' s name is Willie.

Keyword arguments

When a function is called, an argument is specified with the formal parameter, even if the position is wrong, it can be called normally.

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def describe_pet (animal_type, Pet_name):
Print ("\ni has a" + Animal_type + ".")
Print ("My" + Animal_type + "s name is" + pet_name.title () + ".")

Describe_pet (animal_type= ' hamster ', pet_name= ' Harry ')
Describe_pet (pet_name= ' Willie ', Animal_type= ' dog ')

------------------------------------------------------------------------------------------

I have a hamster.
My Hamster ' s name is Harry.

I have a dog.
My Dog ' s name is Willie.

Default value

Specify an argument in the Describe_pet parameter of the SET function, when called

You can call it by default without specifying it.

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def describe_pet (pet_name, animal_type= ' dog '):
Print ("\ni has a" + Animal_type + ".")
Print ("My" + Animal_type + "s name is" + pet_name.title () + ".")

Describe_pet (pet_name= ' Willie ')

------------------------------------------------------------------------------------------

I have a dog.
My Dog ' s name is Willie.

You can also make it easier to call

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def describe_pet (pet_name, animal_type= ' dog '):
Print ("\ni has a" + Animal_type + ".")
Print ("My" + Animal_type + "s name is" + pet_name.title () + ".")

Describe_pet (' Willie ')

------------------------------------------------------------------------------------------

I have a dog.
My Dog ' s name is Willie.

return value

Return Full_name.title () converts the value of full_name to the letter capitalization format

and returns the result to the function call line

Variable Full_name a space between two + middle single quotes in the row

If there are no spaces, the printed effect is also two

-----------------------------------------------------------------

def get_formatted_name (first_name, last_name):
Full_name = first_name + "+ last_name
return Full_name.title ()

Musician = Get_formatted_name (' Jimi ', ' Hendrix ')
Print (musician)

-----------------------------------------------------------------

Jimi Hendrix

Let the parameter become optional

Python interprets a non-empty string as True if there is no middle_name parameter, execute else code

You must ensure that the Middle_name parameter is the last argument

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def get_formatted_name (first_name, last_name, middle_name= "):
If Middle_name:
Full_name = first_name + "+ middle_name +" + last_name
Else
Full_name = first_name + "+ last_name
Return Full_name.title ()

Musician = Get_formatted_name (' Jimi ', ' Hendrix ')
Print (musician)

Musician = Get_formatted_name (' John ', ' Hooker ', ' Lee ')
Print (musician)

-----------------------------------------------------------------------------------------

Jimi Hendrix
John Lee Hooker

Back to Dictionary

----------------------------------------------------------------

def build_person (first_name, last_name):
person = {' First ': first_name, ' last ': last_name}
return person

Musician = Build_person (' Jimi ', ' Hendrix ')
Print (musician)

----------------------------------------------------------------

{' First ': ' Jimi ', ' Last ': ' Hendrix '}

As an example of the above code, add a formal parameter age and set it to an empty string

If the user enters a name, it is added to the dictionary

-----------------------------------------------------------------

def build_person (first_name, last_name, age= "):
person = {' First ': first_name, ' last ': last_name}
If Age:
person[' age ') = Age
return person

Musician = Build_person (' Jimi ', ' Hendrix ', age=18)
Print (musician)

-----------------------------------------------------------------

{' First ': ' Jimi ', ' Last ': ' Hendrix ', ' Age ': 18}

Using functions and while loops together

If the user enters Q, you can exit at any time

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def get_formatted_name (first_name, last_name):
Full_name = first_name + "+ last_name
Return Full_name.title ()

While True:
Print ("\nplease tell Me Your name:")
Print ("(Enter ' Q ' at any time to quit)")

F_name = input ("First Name:")
if f_name = = ' Q ':
Break
L_name = input ("Last Name:")
if l_name = = ' Q ':
Break

Formatted_name = Get_formatted_name (f_name, L_name)
Print ("\nhello," + Formatted_name + "!")

----------------------------------------------------------------------------------

Please tell me your name:
(Enter ' Q ' at any time to quit)
First Name:zhao
Last Name:lulu

Hello, Zhao lulu!

Please tell me your name:
(Enter ' Q ' at any time to quit)
First Name:q

Delivery List

The greet_users () names parameter in the function is just a formal parameter,

And the argument is the list to be passed in

----------------------------------------------------

def greet_users (names):
For name in Names:
msg = "Hello," + name.title () + "!"
Print (msg)

usernames = [' Hannah ', ' Ty ', ' Margot ']
Greet_users (usernames)

----------------------------------------------------

Hello, hannah!.
Hello, ty!.
Hello, margot!.

To modify a list in a function

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Unprinted_models = [' iphone case ', ' Robot pendant ', ' dodecahedron ']
Completed_models = []

While Unprinted_models:
Current_design = Unprinted_models.pop ()
Print ("Printing model:" + current_design)
Completed_models.append (current_design)

Print ("\nthe following models has been printed:")
For Completed_model in Completed_models:
Print (Completed_model)

-------------------------------------------------------------------------------------------

Printing Model:dodecahedron
Printing Model:robot Pendant
Printing Model:iphone Case

The following models has been printed:
Dodecahedron
Robot Pendant
iphone case

Reorganize the above code and call it in a function

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def print_models (Unprinted_designs, completed_models):
While unprinted_designs:
Current_design = Unprinted_designs.pop ()

Print ("Printing model:" + current_design)
Completed_models.append (current_design)

def show_completed_models (completed_models):
Print ("\nthe following models has been printed:")
For Completed_model in Completed_models:
Print (Completed_model)

unprinted_designs = [' iphone case ', ' Robot pendant ', ' dodecahedron ']
Completed_models = []

Print_models (unprinted_designs, Completed_models)
Show_completed_models (Completed_models)

-------------------------------------------------------------------------------------------

Printing Model:dodecahedron
Printing Model:robot Pendant
Printing Model:iphone Case

The following models has been printed:
Dodecahedron
Robot Pendant
iphone case

Pass any number of arguments

-----------------------------------------------------------------------------

def make_pizza (*toppings):
Print (toppings)

Make_pizza (' pepperoni ')
Make_pizza (' mushrooms ', ' green peppers ', ' extra cheese ')

-----------------------------------------------------------------------------

(' Pepperoni ',)
(' mushrooms ', ' green peppers ', ' extra cheese ')

Pass any number of parameters and cycle through the print

----------------------------------------------------------------------------

def Make_pizza (*toppings):
Print ("\nmaking a pizza with the following toppings:")
For topping in toppings:
Print ("-" + topping)

Make_pizza (' pepperoni ')
Make_pizza (' mushrooms ', ' green peppers ', ' extra cheese ')

----------------------------------------------------------------------------

Making a pizza with the following toppings:
-Pepperoni

Making a pizza with the following toppings:
-Mushrooms
-Green Peppers
-Extra cheese

Use positional parameters together with any number of arguments

-----------------------------------------------------------------------------------------------------

def make_pizza (Size, *toppings):
Print ("\nmaking a" + str (size) + "-inch pizza with the following toppings:")
For topping in toppings:
Print ("-" + topping)

Make_pizza (+, ' pepperoni ')
Make_pizza (mushrooms ', ' green peppers ', ' extra cheese ')

-----------------------------------------------------------------------------------------------------

Making a 17-inch pizza with the following toppings:
-Pepperoni

Making a 19-inch pizza with the following toppings:
-Mushrooms
-Green Peppers
-Extra cheese

Use any number of keyword arguments

Define an empty list first

The For loop adds the parameters to the profile dictionary and returns

---------------------------------------------------------------

Def build_profile (First, Last, **user_info):  
     profile = {}    
      profile[' first_name ' = First    
     profile[' last_name '] = Last    
     for key, value in user_ Info.items () :    
          Profile[key] = value    
     return profile

User_profile = Build_profile (' Albert ', ' Einstein ',
Location= ' Princeton ',
Field= ' physics ')
Print (User_profile)

---------------------------------------------------------------

{' first_name ': ' Albert ', ' last_name ': ' Einstein ', ' Location ': ' Princeton ', ' field ': ' Physics '}

Import the entire module

pizza.py file contents are as follows

------------------------------------------------------------------------------------------------------

def make_pizza (Size, *toppings):
Print ("\nmaking a" + str (size) + "-inch pizza with the following toppings:")
For topping in toppings:
Print ("-" + topping)

making_pizzas.py file contents are as follows

----------------------------------------------------------------------------------------

Import Pizza

Pizza.make_pizza (+, ' pepperoni ')
Pizza.make_pizza (' mushrooms ', ' green peppers ', ' extra cheese ')

----------------------------------------------------------------------------------------

Making a 16-inch pizza with the following toppings:
-Pepperoni

Making a 12-inch pizza with the following toppings:
-Mushrooms
-Green Peppers
-Extra cheese

Import a specific function

---------------------------------------------------------------------------------

From pizza Import Make_pizza

Make_pizza (+, ' pepperoni ')
Make_pizza (' mushrooms ', ' green peppers ', ' extra cheese ')

---------------------------------------------------------------------------------

Making a 16-inch pizza with the following toppings:
-Pepperoni

Making a 12-inch pizza with the following toppings:
-Mushrooms
-Green Peppers
-Extra cheese

Assigning an alias to a function using as

--------------------------------------------------------------------

From pizza import Make_pizza as MP

MP (+, ' pepperoni ')
MP (mushrooms ', ' green peppers ', ' extra cheese ')

Assigning an alias to a module using as

------------------------------------------------------------------------------------

Import Pizza as P

P.make_pizza (+, ' pepperoni ')
P.make_pizza (' mushrooms ', ' green peppers ', ' extra cheese ')

Import all functions in a module

-----------------------------------------------------------------------------------

From Pizza Import *

Make_pizza (+, ' pepperoni ')
Make_pizza (' mushrooms ', ' green peppers ', ' extra cheese ')

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Getting started with Python programming to Practice-notes (Chapter 8)