Python tutorial 20: Python Print to file by Manish Sharma

Key Takeaways

what's up Internet i am manish from rebellionrider.com welcome to the second tutorial on Python print function here we will discuss the fourth parameter of the Python plain function which is file here I will show you how to save the output of the Python print function into a file as this tutorial is in the continuation of the last one does a suggest you to watch that tutorial first for a confusion free journey that being said let's start today's tutorial but before we start give this video a thumbs up also help me reaching 200k subscribers by subscribing to my channel if you haven't already now let's start by default the Python print function is designed to show the output on the standard output stream which is almost always the screen of your computer for example here I have two print function calls the first one is set to print a string and the second one contains a mathematical expression if I execute them they will show us the output on our screen like this here is the output displayed to us on our screen there is nothing wrong with this out burn but question here is will this output retain itself for reuse if we do some Kinky's in the function call for example let's see I'm doing some comparison analysis and in that I want to change this multiplication factor from 12 to 12.5 let's see the output now see here we got the output although it's correct but we lost the previous output now that we have lost the previous output we cannot reuse it for comparison this demonstration proves that the Python print function called shows the correct output on the default output is frame but that output is volatile thus we cannot reuse it we just saw the problem with the default Python print function call now let's come to the solution wouldn't it be awesome if we could somehow modify the output stream from printing the output on the screen to saving the output into a file permanently that would solve our problem right my dear friend we can do that using the fourth parameter of Python print function which is file so right now our aim is to redirect the default output stream from showing the output on the screen to saving it into a file for the demonstration we will use the first Python print function call this time we will try to save this string into a file rather than showing it onto the screen let's do that for this demonstration I have created a folder with named Python tutorials in my document directory this folder will be my current project directory inside this folder I will be creating a Python script with the name T UT xx dot py you can create your script and folder wherever you want and name them whatever you want now I will open this script with atom editor here we go now let's write some code here I created a variable and named it file name into this variable we are storing a file object on the right hand side of the assignment operator we have a function called open open is another inbuilt function of Python library which does exactly as its name suggests this function opens a file and returns its file object file object is an object which lets you read write and append data into a file in case the file which you have specified does not exist dentists function will create one for you this function takes two string type parameters first parameter is the name of the file here you can either specify just the name of the file or name of the file with its a location part in my case I have only specified the name of the file which is demo file dot txt it is always recommended to write the name of the file with its extension it's a good practice when you only specify the name like I did here then this function first looks for the file in the directory of your current project which in my case is Python tutorials if it finds the file then it will open it otherwise it will create a new file in that directory second parameter which it takes is open mode this is the mode into which this function opens the files for you the most common open modes are W W stands for write in this mode the file will be open in the write only mode R R stands for read in this mode the file will be open in read-only mode and the third one is e e stands for append this is the mode which I am using here in this mode the function will open the file and append the data to the end of the file mine here if you open the file in write mode then the interpreter will delete all the previously saved data of that file like these three open modes there are four other modes I have explained those in detail in a dedicated blog you can find the link in the description now let's move ahead and complete this code so far this is the same print function call which we have performed before now we have to add the file parameter into it that's all we have to do as I have not created the demo file dot txt file does an execution the interpreter will create one for me in current project directory in addition it will save the output of this Python print function into that let's execute and see the result see there is no output on the screen this time now let's go to my project directory and check if we have demo while dot txt file there with our output or not here we are here we also have the demo file dot txt file let's open it and check if it has the output from our print function saved into it or not here we got the string that's how we redirect output stream and save the output of the Python print function into a file now let's come back to our Python print program great done mind here this redirection of the output stream is temporary which means if you write a print statement without the file parameter next to the one which we just wrote the output of that Python print function will get displayed on to the screen let me show you here I just added another Python print function call on execution the output of the first print function will get appended into file but the output of this second print function will get displayed on your screen let's check see here we got the output that's exactly what I meant when I said the redirection of the stream to a file is temporary stay tuned as in the next tutorial we will learn how to redirect the output stream and save the output of all the Python print function call permanently that's the tutorial on how to write into a file using Python print function hope you enjoyed watching if so then please hit the thumbs up button also share this video on your social media with your friends most importantly I want to hit 100k this year so please subscribe thanks for watching this is manish from rebellionrider.com