Learning environment:
Ubuntu 18.04 system + Geany editor Python 3

Pyhton3 installation:

$ sudo add-apt-repository ppa:fkrull/deadsnakes
$ sudo apt-get update
$ sudo apt-get install python3.5

Geary editor installation:

$ sudo apt-get install geany

Catalog:

• First, list
  • 1. create
  • 2. visit
  • 3. Processing operation
    • 1) Modify element
    • 2) Add element
    • 3) Delete element
    • 4) Sort list
    • 5) Print list
    • 6) Calculated length
  • 4. tuple

First, list

1. create

(1) Character list

(editor display error, single quotation mark of English input method expected)

litters = ['a','b','c']

(2) Number list

Almost any number set you need can be created with range()
<1> Use the function range()+list()
list() converts the result of range() directly to a list

numbers = list(range(1,6))
#Be careful:range(1,6)Access only numbers12345，No,6
print(numbers)

numbers = list(range(1,11,2))
#functionrange()from1Start counting, keep adding2，Until reaching or exceeding11
print(numbers)

<2> Use the function range()

squares = [] #Create an empty list first
for value in range(1,11): #sendrange()ergodic1-10
   squares.append(value**2) #Square the current value and add it to the end of the empty list
print(squares)

The simplified version is as follows:

squares = [value**2 for value in range(1,11)]
print(squares)

2. visit

(1) Forward index access

Note: the element index in the list starts from 0!

letters = ['a','b','c']
print(letters[0]) #First element of output list
print(letters[1]) #Second element of output list
message="The first letter is "+letters[0]+'.'
print(message)

(2) Backward index access

Note: index elements in the list start with - 1!

letters = ['a','b','c']
print(letters[-1]) #Last element of output list
print(letters[-2]) #The penultimate element of the output list
message="The last letter is "+letters[-1]+'.'
print(message)

3. Processing operation

1) Modify element

(editor display error, single quotation mark of English input method expected)

letters = ['a','b','c']
print(letters)

letters[0]='M' #Change the first element in the list to M
print(letters)

2) Add element

append() can add elements to the end of the list
insert() can add elements anywhere in the list

letters = ['a','b','c']
print(letters)

letters.append('T') #Add T to the end of the list
print(letters)

letters.insert(1,'K') #Add K to index as1Location
print(letters)

3) Delete element

(1) del statement delete a location element

letters = ['a','b','c']
print(letters)

del letters[1] #Delete index as1Elements
print(letters)

(2) pop() to delete (pop up) a location element

letters = ['a','b','c']
print(letters)

print(letters.pop()) #Delete the last element of the list and output it
print(letters)
print(letters.pop(1)) #Delete list index as1And output the element
print(letters)

(3) remove() deletes a specified element
Note: only the first specified element can be deleted

letters = ['a','b','c','a','k']
print(letters)

letters.remove('a') #Delete list element a
print(letters)

4) Sort list

(1) sort() permanent sort

letters = ['a','c','m','b','k']
print(letters)

letters.sort() #Sort alphabetically
print(letters)
letters.sort(reverse=True) #Sort alphabetically in reverse order
print(letters)

(2) sorted() temporary sort

letters = ['a','c','m','b','k']
print(letters)
print(sorted(letters)) #Output temporarily sorted list
print(letters)

5) Print list

(1) The entire list includes symbols and elements printed completely

letters = ['a','c','m','b','k']
print(letters)  #Print list

#Reverse list order and print
letters.reverse()
print(letters)

(2) Print out list elements only

letters = ['a','c','m','b','k']
for letter in letters:
     print(letter)

6) Calculation length len()

letters = ['a','c','m','b','k']
print(len(letters))

7) Statistical maximum (list of numbers)

numbers = list(range(1,11))
print(max(numbers))
print(min(numbers))

8) slice

Some elements of the processing list are called slices

letters = ['a','m','d','f','k','g']
print(letters[:]) #Output all elements
print(letters[:2]) #Before output2Element
print(letters[-3:]) #Output final3Element
print(letters[1:4]) #Output index1To index3Elements

9) Copy list

(1) Section method
More flexible. Changing leeters after copying commands will not affect copy

letters = ['a','m','d','f']
copy = letters[:] #Create a slice containing all lists to form a new list copy
letters.append('K')
print(letters)
print(copy)

(2) Direct replication
If you change the letters after copying the command, the copy will also change, that is, the copy is always equal to the letters

letters = ['a','m','d','f']
copy = letters
letters.append('K')
print(letters)
print(copy)

4. tuple

1) definition

Python calls immutable values immutable, and immutable lists tuples

2) comparison

The list uses [] square brackets. After definition, you can modify the list elements
Tuples use () parentheses. Tuple elements cannot be modified after definition (but can be redefined)

letters = ('a','m','d')
print(letters)
for letter in letters:
	print(letter)
	
letters = ('L','k','R') #Redefinition
print(letters)
for letter in letters:
	print(letter)