Python Socket Server Multiple Clients

$ python script. values from server to. This article explains about the working of a simple chatting application, which allows multiple users to chat along. It is, however, necessary to start the IOLoop. TCPServer (server_address, RequestHandlerClass, bind_and_activate=True) ¶ This uses the Internet TCP protocol, which provides for continuous streams of data between the client and server. In particular, the accept() system call returns a new socket object that's actually used for the connection. I have tried. uModbus is very small. Now we will have an example in which the client sends some data to the server and the server handles the data as instructed. The server is built with a synchronous socket, so execution of the server application is suspended while it waits for a connection from a client. This tutorial walks through how you can send data from device-to-device, client-to-server, and vice versa using socket programming in Python. py and ping ws. Just like ZMQ. java" and the "ServerThread. They make the transfer of information possible between two different programs or devices. If any of the client socket is readable then it means that one of the chat client has send a message. c files? First run server. The Socket class provided by Java is used for both clients and servers. To establish a connection to an MQTT broker using the Python client you use the connect method of the client object. It's a state that some sockets can enter and remain in for a relatively long length of time, if you have enough socket's in TIME_WAIT then your ability to create new socket connections may be affected and this can affect the scalability of your client server system. The steps involved in establishing a socket on the client side are as follows:. The objective of this post is to explain how to create a simple socket server using Python and reach it with a client. MPD is configured in the file mpd. py file when i am running the files in both computer then my client computer sending the text message to server computer that is good. IO test client is useful for testing a Flask-SocketIO server. There are numerous Python-based implementations for WebSockets so sometimes it's just easiest to examine an example so you can build something for your own project. Technological stack WebSockets and socket. The server's socket and the client's socket are connected. Hence, we'll keep our focus only on the workflow and example code of the Python TCP server and client. For example, a client connected to a 3-node replica set opens 3 monitoring sockets. values from server to. html somewhere on your hard drive. Example 19-1 accepts a connection request, then serves a single client until that client has finishedother connection requests must wait. Server sockets Server sockets are typically those that expose a service on a network. replace() in python but it didnt work. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. In python, when you send a jpeg file from server to client, you receive as BMP file in client-side, why? I am using socket server and client. thank you in advance (one server and multiple clients) Socket Programming in C, TCP. Wait for him to send some input. PAIR, you could send any number of messages among connected peers or client/server. Python TCP Server with Multiple Clients Please go through the link given at the end of this article in order to understand the need of socket module for TCP Server. There is no client side websockets code yet, but you can test your server with some command line websockets clients or browser extension, e. js found in the dist folder or include it via CDN. A socket is one end of an interprocess communication channel. If any of the client socket is readable then it means that one of the chat client has send a message. Example: UDP Server using Python. It makes the following system calls:. From a server's perspective, at any point in time, it is not unusual for a server to be communicating with multiple clients. socket(socket. The following are code examples for showing how to use http. I know that the TCP server is running on port 8002, and a client connects to the listening server from port 56442. This allows a server to manage connections from a large number of clients simultaneously. Client Socket Basics. server = new. java) sends back the result (message) to the client (Client. Socket and ServerSocket classes are used for connection-oriented socket programming and DatagramSocket and DatagramPacket classes are used for connection-less socket programming. Hence, we’ll keep our focus only on the workflow and example code of the Python TCP server and client. py : #usage: $ python server_multi. print print "typing 'bye' finishes the thread, but not the server ", print "(eg. The “u” or “μ” in the name comes from the the SI prefix “micro-“. I go over how to send valuable information from the client to the server and vice versa. The live server is in use by our cusotmers every day, which makes it impossible to test adjustments and improvements. Python Socket Server. html* and connect to the server. Creating a server from scratch is a big task. The client-server model is one of the most used communication paradigms in networked systems. This is when I write it to a file. This will also only cover the process on windows. connect((SERVER_ADDRESS, SERVER_PORT)) # Compatibility hack. The client-server model is one of the most used communication paradigms in networked systems. I have tried. Clients can open multiple connections by specifying a different namespace on each. 572 Chapter 15 Python programs as network servers Create a web server in Python The web works by using socket network connections, just like those we created in Chapter 14. A socket is one end of an interprocess communication channel. The following is the brief description of the server and the client programs specifically. Technological stack WebSockets and socket. Basically, there are two aspects to a server: handling each established connection, and listening for connections to establish. After you're done reading this article, feel free to check our threaded socket server tutorial! It expands on what you'll learn in this article, and give you an even better understanding of sockets in Python. i have done a small appplication using sockets which works only for a single client and server now i want to do an application that supports multiple clients. Here, I will explain how using sockets a client program can communicate to a server. The server and the client script. (2 sockets are used per client-server) One socket between server and client is exclusively used for the server to get the messages from the client?s message queue and send it to the client thread that receives the chat messages. Trouble Broadcasting Draw Panel To Multiple Clients; How Do You Print Multiple Lines With Readline?. In addition, the RabbitMQ community has created numerous clients, adaptors and tools that we list here for your convenience. However, I've learned that threading doesn't scale very well for hundreds of clients. On the client-side code, we create a client socket using the port argument and connect to the server. At this point, I'm beginning to think: "Python multicast simply does not work. The Squid proxy cache server is an excellent solution to a variety of proxy and caching server needs, and scales from the branch office to enterprise level networks while providing extensive, granular access control mechanisms, and monitoring of critical parameters via the Simple Network Management Protocol (SNMP). The objective of this post is to explain how to create a simple socket server using Python and reach it with a client. The Problem: Low Latency Client-Server and Server-Client Connections. How make my client connect to the server at the same port 2222? I have windows 8, the same machine, the firewall is off, the router is off, no internet, no wifi while I carry out this experiment. py Socket created Socket now listening. I was wondering if you had an idea of how to remove this. When the client connects to the remote server using the public key, the server checks for it and sends an encrypted message which can only be decrypted with the associated private key at the client side. Python Network Programming I - Basic Server / Client : A Basics Python Network Programming I - Basic Server / Client : B File Transfer Python Network Programming II - Chat Server / Client Python Network Programming III - Echo Server using socketserver network framework. PAIR, you could send any number of messages among connected peers or client/server. AF_INET, socket. Client is message sender and receiver and server is just a listener that works on data sent by client. If any of these numbers is different, the socket is different. It plays audio files, organizes playlists and maintains a music database, all while using very few resources. NET Framework. Through this article, you are going to learn how to create a simple server and a client with the help of the Python's socket module. Default recovery procedure can be replaced with a custom one. While at Immersive Labs, Alessio Signorini and I frequently found ourselves having to write custom mini-servers for interactive content. It is designed to easily scale to any number of processes/hosts. Sockets can be configured to act as a server and listen for incoming messages, or connect to other applications as a client. Server channels cannot be used for input or output; their sole use is to accept new client connections. Hence, we’ll keep our focus only on the workflow and example code of the Python TCP server and client. Learn to build a simple socket client, a socket server that handles one connection at a time, and a socket server that can handle mulitple socket connections. Tutorial: Client/Server on the Raspberry Pi. My scenario was as follows. In addition, the RabbitMQ community has created numerous clients, adaptors and tools that we list here for your convenience. socket(socket. After both ends of a TCP/IP socket are connected, communication is bi-directional. Ok, this server can handle only one client at the same time, but it works. io based webserver in Python using the socketio module. The sample code is written in C# and. The “u” or “μ” in the name comes from the the SI prefix “micro-“. routing clients based on their originating address. gethostname() # Get local machine name port = 50000 # Reserve a port. sendEndError(err, callback) Same as socket. Hi, trying to make a chat system with multiple servers. On running above script, run the server_thread1. When run with no arguments, this program starts a TCP socket server that listens for connections to 127. Chat Application - Creating A Chat Server With Multiple Client And With GUI; Send Message To Multiple Clients; Creating A Server To Serve Clients Tutorial; Multiple Clients, Single Server, No Threading; Accept Multiple Clients On A Chat Server. I am using the python client and labview server. This is a very simple Client/Server Chat Application using TCP Sockets Java. Simple Python Socket Functions. This tutorial walks through how you can send data from device-to-device, client-to-server, and vice versa using socket programming in Python. Type gcc server. OpenStackClient utilizes all of the usual OpenStack processes and requirements for contributions. Python - a simple echo server using socket Control-C to kill! # # test your server with the simple client script import socket multiple inheritance; Python. Python simple socket client. The simple way to handle multiple. Once the entire message has been read from the client, the string is displayed on the console and the server socket handling the connection to the client is closed. py and a server. Asynchronous client/server in Python Table of Contents. Some Unix-Like system's interfaces were called through socket interface, e. Python - a simple echo server using socket Control-C to kill! # # test your server with the simple client script import socket multiple inheritance; Python. dispy is a comprehensive, yet easy to use framework for creating and using compute clusters to execute computations in parallel across multiple processors in a single machine (SMP), among many machines in a cluster, grid or cloud. Here is the example of the server side. In addition, the RabbitMQ community has created numerous clients, adaptors and tools that we list here for your convenience. Within the http { } section of your nginx. Hence, we’ll keep our focus only on the workflow and example code of the Python TCP server and client. py --foo sometext - similar as above $ python script. Make a socket application? We will create a simple socket client, that mimics a webbrowser. The Python language has a very clear and expressive syntax as well as alarge and comprehensive library. And why doesn't the process id/description appear when the socket is in FIN_WAIT2 state?. If you have Microsoft SQL Server, you must have encountered this situation where you tell yourself «If only I was able to script all those clicks in Enterprise Manager (aka the MMC) !». SOCK_STREAM) 12 13 # associate the. Now run the server using. Implement a multithreaded server that is capable of serving multiple requests simultaneously. gethostbyname() and socket. html somewhere on your hard drive. Developing servers that scale is usually quite tricky, even more so with Python and the absence of worker threads which can run on multiple cpu cores [1]. Python Network Programming I - Basic Server / Client : A Basics Python Network Programming I - Basic Server / Client : B File Transfer Python Network Programming II - Chat Server / Client Python Network Programming III - Echo Server using socketserver network framework. This is a follow-on from my previous post on Python 3. For testing the program, you can run it on a local server. Now open HTML file in browser and it will connect to socket server. Supports multiple sources: socket, file, audio, USB. Method of creating and opening Sockets are created using socket and assigned their identity via bind. Wait for him to send some input. I built a client application that communicates with this server. A developer discusses how to use a TCP/IP server to multiple requests from the client in parallel on our server, change the localhost to the actual server host and port number. There are two scripts that compose this chat script. org where you can test your clients in a variety of ways: plain MQTT, MQTT over TLS, MQTT over TLS (with client certificate), MQTT over WebSockets and MQTT over WebSockets with TLS. Abstract: This page describes how to write a simple UDP client/server system in a C/Unix environment. In our previous Python socket programming tutorials, we’ve already explained the bit-by-bit details of sockets and writing a socket server/client application. In this tutorial, we will learn how to create a simple HTTP Server in Java, which can listen HTTP request on a port let's say 80 and can send response to client. client_socket, address = server_socket. An UDP client can send "n" number of distinct packets to an UDP server and it could also receive "n" number of distinct packets as replies from the UDP server. The server and the client script. IO protocol supports multiple logical connections, all multiplexed on the same physical connection. We will save python socket server program as socket_server. py Once launched, the server program will wait, listening from incoming connections. Welcome to Java Socket programming example. IO on the server side:. Hey guys, I got a little bored and thought I would to make some of the basic Client/Server applications I have a little bit flashier with a gui interface. This module shows the steps on how to build and develop the C++ and C# UDP client and Server. connect((serverHost, serverPort)) sSock. For example, many web browsers can simultaneously communicate with a single web server using a group of sockets made. We can create it using python's socket and threading modules. Concretely, it is a representation of this endpoint in networking software (protocol stack), such as an entry in a table (listing communication protocol, destination, status, etc. A socket is one end of an interprocess communication channel. The Python language has a very clear and expressive syntax as well as alarge and comprehensive library. I am getting a huge string before the data I need that looks like this \t\u0000\u0000\u0000\t\u0000\u0000\u0000\t. Hence, we’ll keep our focus only on the workflow and example code of the Python TCP server and client. accept() - Server accepts connection request from a client; client_socket is the socket used for communication with client and address the client's address. Demonstration of simple http client (browser) - Python example. see my code bellow,there are three classes,"JavaServer. Example: UDP Server using Python. Further reading. This is very handy when you need to have running daemon on background. Java Socket programming can be connection-oriented or connection-less. Python UDP Socket Serer Why bother to write a UDP server, And do not use Apache Web server Apache or other Java Web Container? Sometime in a real world application environment, create a light weight UDP server or daemon to perform simple tasks -- without all the attached Apache modules running inside an internal network make sense. Hence, we'll keep our focus only on the workflow and example code of the Python TCP server and client. In a different test class, we shall create a test to show that multiple requests to the EchoServer will be served without the server closing the socket. 03/30/2017; 2 minutes to read +8; In this article. TCP provides reliable, ordered delivery of a stream of bytes from a program on one computer to another program on another computer. The Client¶ In your client. How to create an online live server on Digital ocean and run python files on it. In this ESP32 tutorial we will check how to send data with a socket client on the Arduino core. with “Simple WebSocket Client” Chrome extension. Named pipes are created using mkfifo. So far I have just been working with the server and the main problem that I run into is when the program has to enter a loop while waiting for a. I am using the python client and labview server. AF_INET,socket. 1:60267 Starting socket thread ----- In Child Socket Thread Data received from client: Closing the child socket now Successfully closed child socket Since this is a multi-threaded server it can service multiple clients which we now demonstrate using 4 telnet windows, just like we did in the previous article. Server (Server. Bug reports may be submitted to the python-openstackclient Storyboard project. Implement TCP Server and Client Using Python Socket Class. As you can see, coding a TCP server in Python 3 is rather easy. A possible solution are worker processes that duplicate the client's socket, a technique that allows the workers to processes requests and send responses directly to the client socket. gethostname() # Get local machine name port = 50000 # Reserve a port. Re: Multiple clients communicating to one socket The way it works is there's a socket that "listens" on a certain port -- for example, a web server that listens on port 80. The client instance opens one additional socket per server in your MongoDB topology for monitoring the server’s state. The client in socket programming must know two information: IP Address of Server, and; Port number. Since we will need to reach a socket server, we will implement our own using Python. c and client. conf file, you can declare a upstream section with a list of Socket. A socket server is a bit more complicated than is a client, mostly because a server usually needs to be able to handle multiple client requests. On the server side, you will first create a socket and bind to a port, just like UDP. Feathers sets up a normal Socket. Because server and client sockets are created in different ways, I discuss them independently. There are four basic concrete server classes: class socketserver. 0: Producer will not wait for any acknowledgment from the server. IO process you want to balance load between:. The client in socket programming must know two information: IP Address of Server, and; Port number. Sockets are bound to the port numbers and when we run any server it just listens on the socket and waits for client requests. Since we will need to reach a socket server, we will implement our own using Python. You can check in detail how to set a socket server in Python on this previous post. you can quit telnet, run it again and get a different ", print "thread name" print "typing 'quit' finishes the server" try: # # NOTE - No need to declare QUIT as global, since the method never # changes its value # while not QUIT: try: # # Wait for half a second. js from the server. It starts a server which will be always running listening to a port 25000 (Server. This series is designed to teach you how to develop multiplayer online games using python and networking. The “u” or “μ” in the name comes from the the SI prefix “micro-“. Hence, we'll keep our focus only on the workflow and example code of the Python TCP server and client. add_sockets (sockets: Iterable[socket. When the client connects to the remote server using the public key, the server checks for it and sends an encrypted message which can only be decrypted with the associated private key at the client side. Socket in python will only send data it receives. More than two pieces of software can communicate with client/server or distributed systems by using multiple sockets. To handle multiple clients, the server must create a thread per client (this time the thread can be created directly in Python). The server will allow multiple connections. The client script connects to the chat server and communication between the two starts. i have done a small appplication using sockets which works only for a single client and server now i want to do an application that supports multiple clients. A port of a server can be used by many clients (connections). Connected with 127. When writing code using the Paho Python client you would have had to use the loop() function. Sockets (aka socket programming) enable programs to send and receive data, bi-directionally, at any given moment. I said last time I would write a Rails code, but, promise to do that next time. (4 replies) Hi, I tried finding and example of multithreaded client-serve program in python. py Once launched, the server program will wait, listening from incoming connections. It is a very common module and it's most likely. At the end of this tutorial you will have a working game where moving a rectangle on one client will move it on the other. NET Console based application , that can handle multiple clients at the same time. Chat Server using PHP Socket Ok! Now we have our chat page ready to connect to server, but we also need to create a WebSocket server that runs permanently (no time-outs), performs WebSocket handshaking, send/receive data from chat page and handles multiple clients, for that we will create a daemon script in PHP. How to Socket Programming in Python A socket is an endpoint of a two-way communication link between two programs running on the network. It's no big deal, but it's pretty nice because at this point you actually have working websockets server. Using Python threading, first create a main thread in which your modified server listens for clients at a fixed port. It has two parts: a client-side library that runs in the browser, and a server-side library for node. While at Immersive Labs, Alessio Signorini and I frequently found ourselves having to write custom mini-servers for interactive content. It uses actual threads and not select() or some other function. web-socket-js is a Flash-based client-side WebSockets implementation. redis-py provides a connection pooling. Scripting Microsoft SQL Server with Python. The client OS allocates a random local port, chooses a local IP (normally based on which interface the packet will be sent out on) and fills in the remote IP and port requested by the client application. The server talks on 3737 the whole time, which is why only one client can be connected (at least in TCP) and to have multiple clients you need asynchronus or threaded connections. Sockets (aka socket programming) enable programs to send and receive data, bi-directionally, at any given moment. The server program needs to be started first followed by the client program. Hello everybody! Here I am again to show you a simple, or maybe I can say the simplest way to build a server client application using C#. In a different test class, we shall create a test to show that multiple requests to the EchoServer will be served without the server closing the socket. Lets start with the former by creating simple Node. For an updated version go to github. The requests will be interleaved or distributed to both the servers. gethostname() # Get local machine name port = 50000 # Reserve a port. There are four basic concrete server classes: class socketserver. js with this code in server. When called, the client function should open a socket connection to the server. Handling Received Client Data over TCP Socket. The following example program creates a server that receives connection requests from clients. Hey guys, I got a little bored and thought I would to make some of the basic Client/Server applications I have a little bit flashier with a gui interface. I am writing a sort of job queue/scheduler for python, with python clients. 5's new async/await syntax. You can ! It's possible to script in Python whatever you can do in the MMC. io-client is exposed automatically by the socket. Client Socket Basics. Sockets are nicely supported by Python, however, giving us a way to create a new protocol when the vast collection of existing internetworking protocols are inadequate. STOMP Over WebSocket. It provides a clean API for a variety of concurrency and network related tasks. py --foo sometext - similar as above $ python script. First, we assign the file name to a variable. When new messages arrive at the Python MQTT client they are placed in a receive buffer. The application is developed in python. REQ will block on send unless it has successfully received a reply back. In this ESP32 tutorial we will check how to send data with a socket client on the Arduino core. Java Socket programming can be connection-oriented or connection-less. The server runs on a PC with the IP addreess 192. py Socket created Socket now listening. Once the entire message has been read from the client, the string is displayed on the console and the server socket handling the connection to the client is closed. The Client¶ In your client. SUSE Linux Enterprise Server is a multimodal operating system that paves the way for IT transformation in the software-defined era. Run the server socket from the terminal first. Write a TCP Client Socket connection program to server in python. Python TCPServer create TCP welcoming socket server begins listening for incoming TCP requests loop forever server waits on accept() for incoming requests, new socket created on return read bytes from socket (but not address as in UDP) close connection to this client (but not welcoming socket) 2-19 Example App: TCP Server. Send integer values from server to client with sockets in Python the RPi using sockets, from the server (RPi) to the client (computer). The server replies to those messages received. This server listens for port 9999 of all interfaces. The server's socket and the client's socket are connected. server_multi. 572 Chapter 15 Python programs as network servers Create a web server in Python The web works by using socket network connections, just like those we created in Chapter 14. replace() in python but it didnt work. py : #usage: $ python server_multi. With socket zmq. write(data). We can create it using python's socket and threading modules. The code is hosted on OpenStack’s Git server. Now that we have developed both a client and a server sockets, it's time to let them communicate. Client() # asyncio. server_multi. i have done a small appplication using sockets which works only for a single client and server now i want to do an application that supports multiple clients. Further reading. For testing the program, you can run it on a local server. I go over how to send valuable information from the client to the server and vice versa. 6 # out; when all clients are gone, server prints the final string v 7 8 # this is the client; usage is 9 10 # python clnt. You can vote up the examples you like or vote down the ones you don't like. In a previous tutorial we learnt how to do basic socket programming in python. Feathers sets up a normal Socket. The following example program creates a server that receives connection requests from clients. If you don't specify a protocol string, an empty string is assumed. However, we can specify that the telnet client use any port number we want, such as port 80 to communicate with a web server. A possible solution are worker processes that duplicate the client's socket, a technique that allows the workers to processes requests and send responses directly to the client socket. $ python3 client. the server will ask for a set of mathematical question (like "MATH 58+12") where we have to write a client program to answer it in python. But the server model suffers from a fairly major flaw: if multiple clients try … - Selection from Programming Python, 3rd Edition [Book]. There are three main problems: call Python script, pass script output to client and; render output in the client. Feathers sets up a normal Socket. 1 on port 5000. Python UDP Server with Multiple Clients We'll write a UDP Server that is capable of handling multiple clients by extending the functionality of the UDP Server that we wrote in a separate article. You can change the message and send again multiple times. Server channels cannot be used for input or output; their sole use is to accept new client connections. The client program is run at the client-side while the server program runs in the Internet. Example: UDP Server using Python. Demonstration of simple http client (browser) - Python example. Not really getting anywhere with this, i'll post ode for both client and server below. That’s right, destroyed. In this post we are going to write a very simple chat application in python that is powered by sockets. Now that we have developed both a client and a server sockets, it’s time to let them communicate. Write a TCP Client Socket connection program to server in python. A small warning: this is highly unlikely to work well on Windows operating systems. This is very handy when you need to have running daemon on background. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: