Python Basics: List

About 0x00　

The Python list object is the most common sequence that the language provides. A list is an ordered collection of positions related to an arbitrary type of object , and it has no fixed size.

The features of the list can be summarized as four points: 1, ordered set, 2, indexed by offset, 3, nested, 4, type variable.

0X01 Basic Operations

' Captain ' # A List of three Diffirent-type objects # Number of items in the list3

We are able to index, slice, and manipulate the list

>>> L[0]#indexing by Position123>>> L[:-1]#slicing a list returns a new list[123,'Captain']>>> L + ['Heisenberg', 456,'Linux']#Concatention makes a new list too[123,'Captain', 3.14,'Heisenberg', 456,'Linux']>>> L#We ' re not changing the original list[123,'Captain', 3.14] 

0x03 Add action

Generate a new list

>>> a = [1, 2, 3]>>> b = [4, 5, 6]>>> A +b[1, 2, 3, 4, 5, 6]   #generate a new list

Extend method: Receives the parameter and adds each element of the parameter to the original list

>>> a = [1, 2, 3]
>>> B = [4, 5, 6]
>>> a.extend (b)>>> a>>> [1,2,3,4,5,6]

Append method: Add any object to the end of the list

>>> a = [1, 2, 3]
>>> A.append (4)
>>> A
[1, 2, 3, 4]

Insert method: Inserts any object into the list, you can control the insertion position

>>> a = [1, 2, 3]'a')>>> a[' a ', 2, 3]

0x04 Modification and deletion

>>> a = [1, 2, 3]
>>> a[1] = ' Change '
>>> A
[1, ' Change ', 3]

Del: Deletes the element at the specified location by index

Remove: The first matching value of a specified value in the overflow list

Pop: Returns the last element and removes it from list

>>> a = [1, 2, 3, 4, 5, 5]del  a[0]>>> A [2, 3, 4, 5, 5]> >> A.remove (5)>>> a[2,3,4,5] #remove the first matching item

>>> A.pop ()
5
>>> A
[2,3,4]

0X05 member Relations

In,not in to determine whether an element is within the list, returns a Boolean value

>>> a = [1,2,3,4] in atrue not in atrue

0X06 List Push-down

 for  in range (1,11)[1,2,3,4,5,6,7,8,9,10]>>> range (1,11,2) [ 1,3,5,7,9]forif x% 2 = = 1[1,3,5,7,9]

0x07 Sort Flip

Sort: Arrange the list from small to large

Reverse: Arrange lists from large to small

Both of these methods are directly modifying the original list

>>> a = [33,11,22,44]>>> b = a.sort ()>>> a[11,22,33,44] >>> C = a.reverse ()>>> A [44,33,22,11]

Python Basics: List