Sort several data structures in Python, including lists, dictionaries, tuples, sets, and python data structures.

Sort several data structures in Python, including lists, dictionaries, tuples, sets, and python data structures.

List: shoplist = ['apple', 'mango', 'carrot', 'bana']
Dictionary: di = {'A': 123, 'B': 'something '}
Set: jihe = {'apple', 'pear ', 'apple '}
Tuples: t = 123,456, 'Hello'

1. List
Empty list: a = []
Function Method: a. append (3) >>> [3]
A. extend ([3, 4, 5]) >>> [3, 3, 4, 5] Add a list Sequence
A. insert (1, 'Hello') >>> [3, 'Hello', 3,4, 5]
A. remove (3) >>> ['hello', 3,4, 5] Delete the first occurrence 3. If there is no 3, an error is returned.
A. pop () >>> ['hello', 3,4]
A. pop (0) >>> [3, 4]
A. index (4) >>> 1 returns the subscript of the first 4 that appears.
A. count (3) >>> 1 Number of element 3 in the list
A. sort> [3, 4] sorting
A. reverse () >>> [4, 3] reverse Order
How to delete an element
A. remove (3) delete an element by using a value. Delete the first element that is a parameter value.
A. pop () deletes an element by subscript. By default, the last value of the List is deleted. If a parameter is included, the element whose subscript is the parameter value is deleted.
Del a [0] deletes an element by subscript,
Del a [] deletes an element whose subscript is 2 and 3 in table.
Del a [:] delete all elements in List
Del a delete list
List derivation:
Vec = [2, 4, 6]
[3 * x for x in vec if x <6]> [6, 12] 3*2, 3*4
Vec2 = [1, 2, 3]
[X * y for x in vec for y in vec2]> [2, 4, 6, 4, 8, 12, 6, 12, 18]
Derivation of nested list:
Mat = [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
]
Print ([[row [I] for row in mat] for I in [0, 1, 2])
>>> [[1, 4, 7], [2, 5, 8], [3, 6, 9]
Thinking: What are the differences between list (zip) and list (* mat )?
2. tuples
Null tuples: t = ()
Tuples assignment: t = (123,345)
T [0]> 123
3. Dictionary
D = {'jack': 'Jack @ mail.com ', 'Tom': 'Tom @ main.com '}
D ['jack']> 'Jack @ mail.com
D ['Jim '] = 'Jim @ sin.com' >>>> {'Jim ': 'Jim @ sin.com', 'jack': 'Jack @ mail.com ', 'Tom ': 'Tom @ main.com '}

Del d ['Jim '] >>>{ 'jack': 'Jack @ mail.com', 'Tom ': 'Tom @ main.com '}
List (d. keys () returns an unordered list composed of all the keywords in the dictionary.
Sorted (d. keys () returns a list of all the keywords in the dictionary.
Dict () constructor can create a dictionary directly from the key-value Pair
Dict ([('time', 123), ('tiny', 234)]) >>>{ 'tiny': 234, 'Tim': 123}
Derivative dictionary creation:
{D2: d2 + '@ main.com' for d2 in list (d. keys ())}
>>>{ 'Jack': 'Jack @ main.com ', 'Tom': 'Tom @ main.com '}
Exercise: cyclically output the key-value pairs in the dictionary:
For name, email in d. items ():
Print (name, email)
4. Set
Empty set: A = set () ※to create an empty set, you must use set ()
Demo:
Basket = {'apple', 'Orange ', 'apple'} >>>{ 'Orange', 'apple'} note that only one duplicate element is displayed?
'Apple' in basket >>> True
'Pear 'in basket >>> False

Mathematical operations of a set:
A = set ('abcdabca') >>>{ 'C', 'B', 'A', 'D '}
B = {'A', 'B', 'M'} >>>{ 'B', 'A', 'M '}
A-B >>>{ 'C', 'D '}
B-a >>>{ 'M '}
A | B >>>{ 'C', 'D', 'B', 'A', 'M '}
A & B >>>{ 'A', 'B '}
A ^ B >>>{ 'C', 'D', 'M '}
Set derivation:
{X for x in a if x not in 'AB'} >>>{ 'C', 'D '}