Blockchain development in Python

1. Go is an open source programming language, which makes it easy to construct simple, reliable and efficient software. If you want to learn this programming language, you should first find a good tutorial. Brother Lian's go language + blockchain training has recently published a new set of go language tutorial, and the teacher's speaking is very good

with the global hot discussion of the concept of "blockchain", the application of blockchain technology has been quietly added to the daily life scenes such as finance, logistics, credit reference, manufacturing and retail. Some experts have shown that the future blockchain will be closely related to people's lives, and the integration of blockchain technology and people's daily life is the general trend

the popularity of the blockchain market has triggered a large number of talents demand based on blockchain technical personnel, and the popularity of blockchain talents is rising at the speed of light. According to the "2018 blockchain high salary list" released by lagou.com, Tencent, Xiaomi, Suning, Jingdong and other domestic enterprise giants have released many high salary blockchain post demands, trying to explore blockchain related technologies and applications. It is also pointed out in the list that the demand for high salary jobs is mainly based on blockchain related technical jobs, among which Suning and Keda have been given the highest monthly salary of 100k

the huge market demand for technical talents will inevitably lead to the explosive emergence and growth of the whole blockchain training market. Most of the training modes can be divided into online training, traditional IT organization training, and offline short-term training camps, which mainly focus on high-end forms. However, in the process of the hot market evolution, there are also a variety of blockchain training chaos: lecturers' qualifications are watered down, and even the most basic names are not disclosed, the syllabus is opaque, and the teaching quality is shrinking, Unreasonable class arrangement and uneven training fees and so on

with the large-scale development of the whole blockchain training market, brother company ecation, together with Yin Cheng, a senior blockchain expert, and his Tsinghua Shuimu Weiming team, has set up a blockchain college. With its professional and powerful team of technical lecturers, detailed and comprehensive curriculum system, and a large number of authentic enterprise blockchain projects, it aims to deepen the blockchain teaching and training field, And train more professional technical talents for enterprises and society<

Yin Cheng, a senior blockchain technology expert, graated from Tsinghua University, is the dean of brother Lian blockchain college. He once served as Google Algorithm Engineer, the world's most valuable expert in the field of Microsoft blockchain, and the gold medal lecturer of Microsoft tech.ed conference. Proficient in C / C + +, python, go language, sicikit learn and tensorflow. With 15 years of programming experience and 5 years of teaching experience, senior software architect, Intel Software Technology expert, famous technology expert, with many years of working experience in the world's top it company Microsoft Google. He has many years of experience in software programming and lecturing, and has developed many procts in human-computer interaction, ecation, information security, advertising and blockchain system. He has deep experience in project management and R & D, has two AI invention patents, and has practical experience in developing e-money deployed to Microsoft Windows azure. Teaching explanation is in simple language, so that students can apply what they have learned
the first stage: blockchain instry and go programming for 5 weeks
the second stage: cryptography and consensus algorithm for 2 weeks
the third stage: Ethereum source code analysis and development for 3 weeks
the fourth stage: Super ledger and node.js for 2 weeks
the fifth stage: bitcoin & EOS for 4 weeks
the sixth stage: comprehensive actual combat of the project

2.

Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain is an important concept of bitcoin. It is essentially a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of information about bitcoin network transactions, Used to verify the validity of its information (anti-counterfeiting) and generate the next block

if such technology wants to be put into application, the biggest problem is the "Impossible Triangle problem"

that is, scalability, decentralization and security cannot be achieved at the same time, and only two of them can be achieved

most of the existing public chain projects in the market are difficult to put into use on a large scale

3. Go is an open source programming language, which makes it easy to construct simple, reliable and efficient software. If you want to learn this programming language, you should first find a good tutorial. Brother Lian's go language + blockchain training has recently published a new set of go language tutorial, and the teacher's speaking is very good

with the global hot discussion of the concept of "blockchain", the application of blockchain technology has been quietly added to the daily life scenes such as finance, logistics, credit reference, manufacturing and retail. Some experts have shown that the future blockchain will be closely related to people's lives, and the integration of blockchain technology and people's daily life is the general trend

the popularity of the blockchain market has triggered a large number of talents demand based on blockchain technical personnel, and the popularity of blockchain talents is rising at the speed of light. According to the "2018 blockchain high salary list" released by lagou.com, Tencent, Xiaomi, Suning, Jingdong and other domestic enterprise giants have released many high salary blockchain post demands, trying to explore blockchain related technologies and applications. It is also pointed out in the list that the demand for high salary jobs is mainly based on blockchain related technical jobs, among which Suning and Keda have been given the highest monthly salary of 100k

the huge market demand for technical talents will inevitably lead to the explosive emergence and growth of the whole blockchain training market. Most of the training modes can be divided into online training, traditional IT organization training, and offline short-term training camps, which mainly focus on high-end forms. However, in the process of the hot market evolution, there are also a variety of blockchain training chaos: lecturers' qualifications are watered down, and even the most basic names are not disclosed, the syllabus is opaque, and the teaching quality is shrinking, Unreasonable class arrangement and uneven training fees and so on

with the large-scale development of the whole blockchain training market, brother company ecation, together with Yin Cheng, a senior blockchain expert, and his Tsinghua Shuimu Weiming team, has set up a blockchain college. With its professional and powerful team of technical lecturers, detailed and comprehensive curriculum system, and a large number of authentic enterprise blockchain projects, it aims to deepen the blockchain teaching and training field, And train more professional technical talents for enterprises and society<

Yin Cheng, a senior blockchain technology expert, graated from Tsinghua University, is the dean of brother Lian blockchain college. He once served as Google Algorithm Engineer, the world's most valuable expert in the field of Microsoft blockchain, and the gold medal lecturer of Microsoft tech.ed conference. Proficient in C / C + +, python, go language, sicikit learn and tensorflow. With 15 years of programming experience and 5 years of teaching experience, senior software architect, Intel Software Technology expert, famous technology expert, with many years of working experience in the world's top it company Microsoft Google. He has many years of experience in software programming and lecturing, and has developed many procts in human-computer interaction, ecation, information security, advertising and blockchain system. He has deep experience in project management and R & D, has two AI invention patents, and has practical experience in developing e-money deployed to Microsoft Windows azure. Teaching explanation is in simple language, so that students can apply what they have learned.

4. Go language is the mainstream language of blockchain
according to the data survey of boss Research Institute, go and C + + are the mainstream languages of blockchain Posts currently recruited. The early blockchain system and application
programs are mainly implemented in C + +, and now most companies will use go language to
build public chain systems<
C + + is suitable for the development of local programs.
go language is suitable for the development of network programs and local programs.
compared with C + + go, it has the following advantages:
garbage collection
clear meaning
unified format

disadvantages:
efficiency is not as high as C + + at present, but for desktop programs, efficiency is not a big problem, Because hardware is fast growing.

C + + is the mainstream language at present, and I believe it will become a classic just like C.
to become a classic means that people who learn it can get a good salary, but it is only good for themselves.
in the future network world, go will have a big chance to get hot, I think it has a bright future.

the developers of go, including the founders of UNIX and C language, are the first generation of hackers, and I believe they will do a good job.

now the go stack + blockchain market is out of an unprecedented gale, and the situation is gratifying.

5. Go language + blockchain training course:
from the characteristics of the language itself, go is a very efficient language, which highly supports concurrency. Go language itself pays more attention to distributed systems, and concurrency processing is relatively good, such as advertising and search, which are high concurrency servers
go language advantages:
excellent performance, can be directly compiled into machine code, does not rely on other libraries, go is extremely fast. Its performance is similar to Java or C + +
concurrency is supported at the language level, which is the biggest feature of go. It is born to support concurrency, and go is the concurrency supported in gene, which can make full use of multi-core and make it easy to use concurrency
the built-in runtime supports garbage collection, which is one of the features of dynamic language. Although GC is not perfect at present, it is enough to cope with most of the situations we can encounter, especially GC after go1.1
it's easy to learn. The authors of go language all have the gene of C, so go naturally has the gene of C. There are 25 go keywords, but the expressive ability is very strong. It almost supports most of the features you've seen in other languages: inheritance, overloading, object, etc
rich standard libraries, go has built a large number of libraries, especially the network library, which is also my favorite part< As like as two peas, br / > built-in powerful tools, Go language is built with many tools chain, the best should be gofmt tools, automatic formatting code, make team review become so simple, code format is exactly the same, it is very difficult to think differently.
cross platform compilation and fast compilation. Compared with the sluggish compilation speed of Java and C + +, the fast compilation time of go is a major efficiency advantage
disadvantages of go language:
package management: package management of go language is absolutely not perfect. By default, it has no way to make a specific version of the dependency library, nor can it create replicable builds. In contrast, python, node and Ruby all have better package management systems. However, with the right tools, the package management of go language can also perform well
lack of development framework: go language does not have a major framework, such as Ruby's rails framework, Python's Django framework or PHP's laravel. This is a heated discussion in the go language community, because many people think that we should not start with using frameworks. This is true in many cases, but if you just want to build a simple crud API, it's much easier to use Django / djrf, rails laravel, or Phoenix
exception handling: go language can help developers deal with compilation errors by simply returning errors (or call stack) through functions and expected calling codes. Although this method is effective, it is easy to lose the scope of the error, so it is difficult to provide meaningful error information to users. Error package can solve this problem by allowing us to add context and stack trace to return error
another problem is that we may forget to handle errors. Static analysis tools such as errcheck and megacheck can avoid these errors. Although these solutions are very effective, they may not be the right way.

6. Initial blockchain
features:
blockchain is an immutable and orderly chain record composed of block records. The main features are as follows:
1: decentralization
e to the use of Distributed Accounting and storage, there is no centralized hardware or management organization, the rights and obligations of any node are equal, and the data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system. Thanks to the decentralization of blockchain, bitcoin also has the characteristics of decentralization
2: openness
the system is open, in addition to the private information of the parties to the transaction is encrypted, the data of the blockchain is open to all, and anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
3: autonomy
blockchain adopts consensus based specifications and Protocols (such as a set of open and transparent algorithms) to enable all nodes in the whole system to exchange data freely and safely in a de trusted environment, so that the trust in "people" is changed into the trust in machines, and any human intervention does not work
4: information cannot be tampered with
once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid, so the data stability and reliability of the blockchain are extremely high
5: anonymity
since the exchange between nodes follows a fixed algorithm, their data interaction does not need to be trusted (the program rules in the blockchain will judge whether the activity is effective by themselves), so the counterparties do not need to make the other party trust themselves by disclosing their identities, which is very helpful for credit accumulation
compared with the traditional distributed database, there are two main differences:
1: the traditional distributed database supports adding, deleting, checking and modifying, while the blockchain only supports searching and inserting, and blocks cannot be deleted or modified
2: the traditional distributed database is generally a master-slave structure: master and slaves structure. In order to ensure high availability, it is realized by standby master, while the blockchain is a decentralized database. There is no master-slave structure
blockchain and bitcoin:
when it comes to blockchain, most people talk about bitcoin. However, blockchain is not equal to bitcoin. It is now the era of blockchain 3.0, and bitcoin is only the proct of blockchain 1.0
the evolution mode of blockchain is:
& ᦇ 9642; Blockchain 1.0 digital currency; Blockchain 2.0 digital assets and smart contracts; Blockchain 3.0 - Implementation of distributed applications in various instries
classification of blockchain:
public blockchains
public blockchain means that any indivial or group in the world can send transactions, and transactions can be effectively confirmed by the blockchain, and anyone can participate in its consensus process. Public blockchain is the earliest and the most widely used blockchain. The virtual digital currencies of bitcoin series are all based on public blockchain. There is only one blockchain corresponding to this currency in the world
consortium blockchains
instry blockchains: multiple preselected nodes are designated as bookkeepers within a certain group, and the generation of each block is jointly determined by all preselected nodes (preselected nodes participate in the consensus process). Other access nodes can participate in transactions, but not the bookkeeping process (essentially, trusteeship bookkeeping), It just becomes distributed accounting, the number of preselected nodes, and how to determine the bookkeeper of each block to become the main risk point of the blockchain). Anyone else can conct limited query through the open API of the blockchain
private blockchain: it only uses the general ledger technology of blockchain for bookkeeping. It can be a company or an indivial, enjoying the write permission of the blockchain. This blockchain is not very different from other distributed storage schemes Dec2015) conservative giants (traditional finance) want to experiment with private blockchain, while the application of public chain, such as bitcoin, has been instrialized, and the application procts of private chain are still groping.

7. Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. The so-called consensus mechanism is a mathematical algorithm to establish trust and obtain interests between different nodes in the blockchain system
and Python is an object-oriented interpretive computer programming language
it's better to learn together without conflict. I think it's Python because it's a language that can do a lot of things.

8. 当然可以
1 import hashlib as hasher
2 import datetime as date
3
4 # Define what a Snakecoin block is
5 class Block:
6 def __init__(self, index, timestamp, data, previous_hash):
7 self.index = index
8 self.timestamp = timestamp
9 self.data = data
10 self.previous_hash = previous_hash
11 self.hash = self.hash_block()
12
13 def hash_block(self):
14 sha = hasher.sha256()
15 sha.update(str(self.index) + str(self.timestamp) + str(self.data) + str(self.previous_hash))
16 return sha.hexdigest()
17
18 # Generate genesis block
19 def create_genesis_block():
20 # Manually construct a block with
21 # index zero and arbitrary previous hash
22 return Block(0, date.datetime.now(), "Genesis Block", "0")
23
24 # Generate all later blocks in the blockchain
25 def next_block(last_block):
26 this_index = last_block.index + 1
27 this_timestamp = date.datetime.now()
28 this_data = "Hey! I'm block " + str(this_index)
29 this_hash = last_block.hash
30 return Block(this_index, this_timestamp, this_data, this_hash)
31
32 # Create the blockchain and add the genesis block
33 blockchain = [create_genesis_block()]
34 previous_block = blockchain[0]
35
36 # How many blocks should we add to the chain
37 # after the genesis block
38 num_of_blocks_to_add = 20
39
40 # Add blocks to the chain
41 for i in range(0, num_of_blocks_to_add):
42 block_to_add = next_block(previous_block)
43 blockchain.append(block_to_add)
44 previous_block = block_to_add
45 # Tell everyone about it!
46 print "Block #{} has been added to the blockchain!".format(block_to_add.index)
47 print "Hash: {}\n".format(block_to_add.hash)

9. /**
******************************************************************************
* @file stm32_eth.c
* @author MCD Application Team
* @version V1.1.0
* @date 11/20/2009
* @brief This file provides all the ETH firmware functions.
******************************************************************************
* @
*
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
* TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
* DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
* FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
* CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*
* <h2><center>© COPYRIGHT 2009 STMicroelectronics</center></h2>
*/