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- [Instructor] Next we're
going to take a look at

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serializing a Python object
into JavaScript Object Notation,

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and for this demonstration,

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we'll be writing that
object into a text file.

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So first of all, we've
created a Python dictionary

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in this case, that we'll be writing out

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as JavaScript Object Notation.

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The accounts dictionary consists
of a set of curly braces.

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In that set of curly
braces, we have one key,

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which is the accounts

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key, and its value is a
list of other dictionaries,

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and those two dictionaries
represent records of information

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in our accounts dictionary.

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So in the accounts dictionary,
the accounts key has a list

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as its object, its value,
and within that list

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we have a dictionary that
represents one account with the

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account number 100, the name
Jones and the balance 24.98,

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and a second account, which
has the value 200 for the

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account number, the name
Doe and the balance 345.67.

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So let's now take a look at
working with the JSON module,

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so we're going to import that module,

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and let's use a with statement
to open up a file for writing

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and output the dictionary

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in JavaScript Object Notation format.

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So as you can see here we're
opening the file accounts.json.

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We're using .json as the
file name extension here,

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but there is no specific
required format or

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extension for a file
containing JSON objects.

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We're opening for writing,
so that's going to

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create the file if it doesn't exist,

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and otherwise it's going to wipe out

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the contents of an existing file,

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and we're going to reference
that file object as accounts.

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Now in the JSON module, there is a method,

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or function, rather, called
dump, which takes two arguments.

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The first is the Python
object that we want

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to turn into JavaScript Object Notation,

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and the second is the
file object into which

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we are going to write that information.

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So we'll go ahead an execute that,

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and remember that's automatically going to

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close the file once we're done,

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and now let's just go ahead
and display the contents

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of that accounts.json
file so that we can see

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what it looks like out
on disc, if you will.

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By the way again, cat, for
those of you who are using

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Linux and Mac OS, and you would use more

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for those of you who are on Windows.

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Now as you can see here,

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we have just a long string of information.

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JSON is just a big string of data,

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and in this string of information
we have the key accounts,

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which was the key in our dictionary.

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We have now a JavaScript
Object Notation list,

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and within that JavaScript
Object Notation list,

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we have here a JSON object.

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Every JSON object is
delimited by curly braces.

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This JSON object has three
name value pairs as part of it.

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Then we have another
JSON object in that list,

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which also has three name
value pairs as part of it.

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So it looks just like
the dictionary up above.

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The main difference is that we
have double quote characters

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instead of single quote characters,

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because in JavaScript Object Notation,

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you must use double quote
characters for strings.

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In the next video, we'll take a look at

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reading this JSON object back into our

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iPython session.