Python Tutorial - 14. Working With JSON

Key Takeaways

hello everyone welcome to core Basics coding tutorials today's topic is working with Json objects in Python and here is the list of items we are covering in this video let's begin with what is Json full form of Json is Javascript object notation it is a data exchange format similar to XML let's understand this by looking at and address record we have this person called Tom and here is his his address book record the way you represent this in Json format is you will have bunch of keys so here name address phone R keys and there are corresponding values which is Tom his address and the phone number the Json object opens and closes with this curly brackets here is the similar representation of the same object in XML format as you can see here in XML the difference is each of these keys are represented as opening and closing tags that's why this takes up lot more volume of data and hence it is not as lightweight as as Json Json is much more lightweight and that's the reason why Json is gaining a lot of popularity nowadays okay now let's work on a problem of creating an address book so we what we're going to do is we'll create an address book we'll write bunch of Records into it and then we will save it as a file on our computer then we will write a second program to read that address book and print those address book records okay so first I'm going to create a dictionary object there is no object called a Json in Python Python's native objects are either numbers strings dictionaries Etc Json is just a concept Json is basically a a format which is implemented by different languages so all C++ JavaScript python all languages supports it but otherwise it's it's a very generic concept versus dictionary is just specific to python okay here in this dictionary we will add a first track cord for Tom and we'll say his name is Tom his address is this and the phone number is this okay let's create another object another record rather in our book dictionary and we are going to call it Bob and Bob's address is this okay let's type in some random phone number okay now what we will do is we will import a Json module so that is the standard module available in Python called Json and once imported you can call this method called dump s what this is doing is it is taking dictionary object which is book as an input then it is dumping it as a string that's why we have a string here and when it converts this dictionary object into a string it will convert it into a Json format that's why we have we are using Json module here so when you say s equal to this the string s will be in Json format let's first print it and see how it looks when you say run address as you can see here in the output this thing is a big string but it is in a Json format it has all opening closing brackets columns to separate keys and values and so on okay now we will write this to a file so I'll just remove this and I'll say with open C data book. dxt we are going to save this address book in C datab book. txt file and if you remember from my file tutorial if you want to write to a file you have to use W here you will just say f. write s so this will write this string Json string to a file let let's execute this excellent it says program finished with exit Code Zero means there were no errors now let's go and check our C data directory so I have C data directory here and I'm seeing book. txt file if I open it I see the content that I wrote to that file this content is in a gson format the advantage now is that once you have content into a gs1 format format you can write a C++ program or let's say JavaScript program to open this and read the the the those objects successfully okay that's why it's called Json is a data exchange format so you can exchange data from your Python program to C program okay but here to read that we are going to use another Python program uh and for that I will use idle so let me bring my idle here here and using idle I will write another program that reads those records one by one okay so again you have to use uh you have to first open the file and this time I will use R because I'm reading it for writing you use W okay you will say s equal to f. read this is going to read the whole file into this variable called s if you print s it looks like this you have entire files contain into this variable now if you want to leten know Bob's phone number you have to use a Json module to read this Json string and pass it into a Json object okay so I will import Json module here and I will use another matter called Json do load string that's why it is load as load string s okay and once it loads it what it will do is it will convert that string into our dictionary so I will say book okay if I print book here the difference between this output and the next output is this guy was a Str Str versus this guy here is a dictionary you can confirm it using type function type of book is a dick all right how do I know Bob's phone number first let's print Bob's entire address book record when you do this it is printing the whole address book record for Bob okay if you want to now know the phone number you will say Bob and phone okay this is printing his phone number once you convert it to a dictionary object it is very easy to access the information within that big object using the keys and that that's a power of Json and dictionaries all right next thing we are going to do is now we are going to print all the address book records in our book for that you have to use for Loop you will say for person in book print book person this is going through all of the keys in the dictionary 1 by one and we are printing the corresponding values excellent so it's printed all these records one by one you can have like hundreds of records and it will still work fine okay so that was all about Json object we covered how to read and how to write Json objects and how to convert them to dictionary back and forth okay thanks for watching