python learning path
Because of work, my studies have been stagnant for a long time and I have fallen behind a lot. Really, it is important to learn to persevere. There are too many temptations around us and any difficulty may become a reason to give up. Let yourself keep walking, no matter how small the steps are, as long as you walk, there is hope. Give it to yourself and fight to the end.
Collection
A collection is an unordered, non-repeating data combination. Its main functions are as follows:
Remove duplication, turn a list into a set, and it will automatically remove duplication
Relationship testing, test the intersection, difference set, and Union and other relations
Change the list into a set
list_1 = [1,4,5,7,3,6,7,9] liset_1 = set(list_1) print(list_1,type(list_1)) >>>
[1, 4, 5, 7, 3, 6, 7, 9]
Process finished with exit cod
Intersection
list_1 = [1,4,5,7,3,6,7,9]
liset_1 = set(list_1)
list_2 = set([2,6,0,66,22,8,4])
print(list_1,list_2)
list_1.intersection(list_2)
print( list_1.intersection(list_2 ))
>>>
[4,6]
Union
list_1 = [1,4,5,7,3,6,7,9]
liset_1 = set(list_1)
list_2 = set([2,6,0,66,22,8,4 ])
print(list_1.union(list_2))
>>>
[0,1,2,3,4,5,6,7,66,9, 8,22]
Difference set
list_1 = [1,4,5 ,7,3,6,7,9]
liset_1 = set(list_1)
list_2 = set([2,6,0,66,22,8,4])
print(list_1. difference(list_2))
>>>
[1,3,5,9,7]
Subset
list_1 = [1,4,5,7,3,6,7,9]
liset_1 = set(list_1)
list_2 = set([2,6,0,66,22,8,4])
print(list_1.issubset(list_2))
>>>
false
parent set
list_1 = [1,4,5,7,3,6,7,9]
liset_1 = set(list_1)
list_2 = set([2 ,6,0,66,22,8,4])
print(list_1.issuperset(list_2))
>>>
false
Symmetric difference set
list_1 = [1,4,5,7,3,6,7,9]
liset_1 = set(list_1)
list_2 = set([2,6,0,66,22,8,4])
print(list_1.issubset(list_2))
>>>
[0,1,2,66,3,5,7,9,22]
##It is judged that there is no intersection
print("-----------")
list_3 = set([1,3,7])
##list_4 = set([5,6,8])print(list_3.isdisjoint(list_4))
>>>
true
Of course, the operation can also be completed using symbols:
s = set([3,5, 9,10]) #Create a set of values
t = set("Hello") #Create a set of unique characters
a = t | s #The union of t and s
b = t & s #The intersection of t and s
c = t – s # Find the difference set (The term is in t, but not in s)
d = t ^ s # Symmetric difference set (the term is in t or s, but does not appear in both at the same time)
Basic operations:
t.add('x') # Add an item
s.update([10,37,42]) # Add in s Multiple items
Use remove() to delete one item:
t.remove('H')
len(s)
The length of set
x in s
Test whether x is a member of s
x not in s
Test whether x is not a member of s
s.issubset(t)
s <= t
Test whether every element in s is in t
s.issuperset(t)
s >= t
Test whether every element in t is in s
s.union(t)
s | t
Return a new set containing every element in s and t
s.intersection(t)
s & t
Return a new set containing common elements in s and t
s.difference(t)
s - t
Return a new set containing elements that are in s but not in t
s.symmetric_difference(t)
s ^ t
Return a new set containing s and t Unrepeated elements
s.copy()
Returns a shallow copy of set "s"
The above is the detailed content of python learning path. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Solution to permission issues when viewing Python version in Linux terminal When you try to view Python version in Linux terminal, enter python...

When using Python's pandas library, how to copy whole columns between two DataFrames with different structures is a common problem. Suppose we have two Dats...

Getting started with Python: Hourglass Graphic Drawing and Input Verification This article will solve the variable definition problem encountered by a Python novice in the hourglass Graphic Drawing Program. Code...

Choice of Python Cross-platform desktop application development library Many Python developers want to develop desktop applications that can run on both Windows and Linux systems...

Many developers rely on PyPI (PythonPackageIndex)...

Data Conversion and Statistics: Efficient Processing of Large Data Sets This article will introduce in detail how to convert a data list containing product information to another containing...

How to handle high resolution images in Python to find white areas? Processing a high-resolution picture of 9000x7000 pixels, how to accurately find two of the picture...

When using Python to connect to an FTP server, you may encounter encoding problems when obtaining files in the specified directory and downloading them, especially text on the FTP server...
