Never write code , To be able to write code to solve problems independently . This question is very important ！ Blind learning of so-called projects , Finally, I still can't write my own code to solve the problem . First of all, we solved the problem of writing code independently , Then through the project to strengthen training .
O & M must understand development , especially python Development , We have reached a consensus , Do not understand the operation and maintenance of development , The road will get narrower and narrower .
The difficulties encountered in some o & M are ： Some don't even understand books ; Some books can be read , Simple code written by others can also be understood , But I can't write code to solve problems .
The author believes that learning programming is more than learning grammar , Need to learn algorithms （ Computational Thinking 、 Solutions to problems 、 Programming ideas ）.
What is Computational Thinking ：
Computational Thinking （Computational Thinking） The concept is a natural product of the development of computer science .
It was Carnegie who first clearly used this concept · Zhou Yizhen of Mellon University （Jeannette M. Wing） professor . For novices, Xiaobai wants to learn more easily Python Basics ,Python Reptiles ,web Development 、 big data , Data analysis , Artificial intelligence and other technologies , Here to share the system teaching resources , Take off my lieutenant （ Tongying ）： 2763 177 065 【 course / Tools / Method / Solve the problem 】
Computational thinking is to use the basic concepts of computer science to solve problems 、 Designing systems and understanding human behavior ;
The most fundamental content of Computational Thinking , That is, its essence is abstraction and Automation .
Programming ideas , In fact, it is the concrete embodiment of computational thinking , Use grammar to express solutions to problems 、 Algorithm .
Let's talk about how to learn python
1、 Buy a good book , Recommend 《python Programming core 》, One book is enough .
2、 While reading , You need to tap the code , Every code in the book needs to be typed , In the process of knocking , To encounter problems . Problems encountered , Find a solution to , To improve .
3、 We also need to do proper exercises to strengthen our study .
4、python There are many programming paradigms , Process oriented , object-oriented , Functional programming, etc . It is suggested to start with process oriented learning .
Some friends aim high , Even the basic logical expression is not clear , Circulation and judgment are not clear , Just want to learn django.
Question 1 :
Output the following styles 1,2,3,4,5,6,7,8,9,10
Many beginners , Will write the following code ,
for i in range(1, 11): print str(i) + ",",
The output is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
I don't know how to output the last comma . Tell you , I know when I read if Judgment statement , But the practical application is not good .
Analyze this style 1,2,3,4,5,6,7,8,9,10 The last one has no comma , There is a comma in front of it , This is obviously a judgment . For novices, Xiaobai wants to learn more easily Python Basics ,Python Reptiles ,web Development 、 big data , Data analysis , Artificial intelligence and other technologies .
So the code is written like this ：
n = 10 for i in range(1, n+1): if i < n: print str(i) + ",", else: print str(i) Question two ：
Counting cycle , I believe most of the toy codes in the book can be understood .
The following question , Beginners do not necessarily think of using counting loops to solve this problem .
Code 1 ：
A couple M Text file for , It needs to be every 100 Lines are written to the new file .
Don't underestimate the counting cycle , This problem can be solved by counting loops and judging statements .
coding:utf-8
with open('dist_1.txt','r') as f1 ,open('dist_new.txt','w') as f2: i = 0 for line in f1: i += 1 if i % 100 == 0: f2.write(line)Code 2 ：
A log text file has 2000 That's ok , I want to extract 100 Row to 200 That's ok , How do you do it? ？
You can try the following methods .
Don't look down on while Count cycle , In fact, it can be used to do many things .
#coding:utf-8 i = 0 file1 = open("test.txt","r") file2 = open("out.txt","w") while True: line = file1.readline() i += 1 if 100<=i and i<=200: file2.write(line) if i >200 : break if not line: break file1.close() file2.close() 5、 Function abstraction 、 We need to master how to resolve big problems into small ones , Every little problem is solved by a function , The big problem will be solved by integration .6、 Object oriented class abstraction , A class is the blueprint of an object composed of attributes and methods . Be able to model with object-oriented ideas .
summary ： Is there a programming idea , It is the key to whether you can write code yourself . Master some common simple algorithms ： Exhaustive method , Dichotomy , recursive algorithm , A recursive algorithm , Backtracking algorithm and so on ;
