Python Learning Notes (v)--list and tuple

A, list 1, definition:

List is an ordered set of elements that can be added and removed at any time

2. Declaration method:

subjects=['Math','中文版'Chinese  ']

3. Some API (1) Gets the number of list elements

Len (subjects)

(2) using an index to access the elements of each position in the list, remember that the index is from 0Started with

Subjects[0]

PS: If you want to take the last element, in addition to the index location, you can also be -1 indexed, directly get the last element, -2 is the penultimate, and so on.

(3) Append the element to the list to the end:

Subjects.append ('Music')

(4) inserting the element into the specified position

' Music ')

(5) Delete the element at the end of the list

Subjects.pop ()

(6) To delete the element at the specified position

Subjects.pop (i)

(7) to replace an element with another element, you can assign a value directly to the corresponding index position

' Music '

(8) The data type of the elements in the list can be different

(9) The IST element can also be another list

p = ['asp''php'= ['python'  'java'scheme']s[2][1]  # equivalent to a 2-D array

Second, tuple1, definition

Another ordered list is called a tuple: a tuple. Tuple and list are very similar, but a tuple cannot be modified once initialized

2. Statement

subjects= ('Math','中文版'Chinese  ')

3, the advantages of the tuple

The tuple is immutable, so the code is more secure

4. Tuple traps

(1) When you define a tuple, the elements of the tuple must be determined at the time of definition.

(2) When you define a tuple of only one element, you must write to the following format, otherwise the operation is performed () by default.

Tuplee = (1,)

(3) A tuple refers to the data that is pointing to the same, that is, when a tuple contains a list

Python Learning Notes (v)--list and tuple