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In this video, we'll see another 
way to store data in a text file. 

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This time, we'll use the write method.
I'll continue in the same Python file, 

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and start by commenting out all the code 
from the last video, except for the list. 

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This time, I'll call the 
output file flowers_write.txt. 

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That will let us see the difference 
between data that we've stored using print, 

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and the data in this video, 
that will be stored using write. 

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That's very similar to our 
earlier code, on lines 25 to 27. 

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Once again, we iterate over the items in 
the list, and store each item in the file. 

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This time, we use the write method 
of our file object – plants. 

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The code's very similar, but the 
results will be a bit different. 

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Run the program, and let's see what we get.
Just as before, the text file gets created. 

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Double-click flowers_write.txt, in the 
Project pane, to open it in our editor. 

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That's definitely different to our previous file!
Instead of each plant on a new line, 

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we've got a single line of text, with each plant 
written immediately after the previous one. 

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That's the most obvious difference 
between using print and using write. 

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The write method only sends exactly 
what you specify, to the file. 

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print performs various conversions 
on the data, and includes things 

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like line breaks, and separators.
Notice that I didn't just mention 

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"line breaks and separators" there.
I also mentioned "various conversions". 

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The print function calls a special method, that 
all objects have, before printing the object. 

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The method's called __str__.
You'll learn the reason for that strange name, 

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with underscores, in the OOP section.
What the method does, is return a string 

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representation of the object. That's what 
allows print to print objects to the screen. 

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I'll add some code, to give some examples of this.
Back in IntelliJ, I'll print our data list: 

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Run the program

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and we can see the string representation
of our list, in the output. 

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The string representation encloses the list 
in square brackets – which is what we use to 

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define our list. So when we print a list, 
it looks how we'd expect a list to look. 

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Each string item in the list is enclosed in 
single quotes, and they're separated by commas. 

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Let's check what that __str__ method returns, 
just to be clear about what print is doing for us: 

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Run the program
and string_representation is a string. 

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So why am I telling you all this?
Remember that text files can only hold text. 

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If you try to put numbers into 
a text file, things don't work. 

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But you can put the string representation 
of a number into a text file. 

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That means we can print numbers to 
a file, but we can't write them. 

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I'll finish this video by demonstrating that. 
Comment out the existing code, and we'll try to 

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print, and write, numerical values to a text file.

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That looks straightforward. We print the numbers
from 0 to 9, to a text file called test_numbers.txt. 

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Run the program,
and open test_numbers.txt in IntelliJ. 

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No surprises there. The print function obtained 
the string representation of each number, 

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and sent it to the file. Because print automatically 
adds a newline, each number is on a new line. 

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If we do the same thing with the 
write method, it doesn't work: 

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You may get a warning from your IDE, on line 53, 

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that a string type was expected.
We're writing to a text file, 

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which means we can only put strings into it.
But let's run the program, and see what happens. 

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And we get a TypeError: "write() 
argument must be str, not int". 

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The print function will print 
the string representation 

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of any object that you ask it to print.
In addition, it will include a separator between 

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multiple arguments – the default is a space, but 
that can be changed with the sep keyword argument. 

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Finally, it will print the value 
of the end keyword argument. 

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The default is a newline character. 

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The write method will only write 
exactly what you tell it to write. 

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No separators or newline characters are included, 
unless you explicitly tell it to write them. 

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Also, no conversion is performed. If 
you tell write to write an integer, 

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that's what it will try to send to the file.
If the file is opened in text mode 

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(the default), you'll get an error if 
you try to write numerical values to it. 

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So which should I use, write or print?
The answer to that is, use whichever is more 

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convenient for the task you're trying to perform.
If you want complete control over 

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what gets written, use write.
If it's more convenient to let print include 

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separators and newline, and convert objects to 
their string representations, then use print. 

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Those are guidelines, there are no rules. 
The same is true of human languages. 

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For example:
"Do you want to come to the movies with me?" 

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and
"I'm going to the movies, do you want to come?" 

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both convey pretty much the same thing. 
There are subtle differences, but generally 

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you could phrase the question either way.
The first might be more appropriate if you 

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were asking for a date. The second makes your 
intention – to see a movie – more explicit. 

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You're going to the movies, regardless 
of the answer to the second question. 

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Ok, back in IntelliJ, I'll 
change that code to write 

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the string representation of our integer values. 

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To get the string representation of 
an object, we use the str function: 

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Run the program, and let's see what we get.
Open test_numbers.txt, 

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and we've got each number printed.
Note that there are no spaces or newline characters. 

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The write method writes exactly what 
we tell it to write – nothing less, nothing more. 

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If you want each number on a new line, you 
have to explicitly write the newline character. 

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One way to do that, is to concatenate the 
newline onto the string we're writing: 

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Run the program again.
Then check test_numbers.txt. 

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Now, each number is on a new line.
Ok, we've seen two different ways to 

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write to a text file, and discussed 
the main differences between them. 

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One thing you might be wondering is, what 
happened to the numbers that we printed, 

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on lines 47 to 49 of our code?
I'll switch back to save_flowers.py in IntelliJ. 

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On lines 47 to 49, we printed 
the numbers to the file. 

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But when we ran the program, after 
adding the code on lines 51 to 53, 

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those numbers had disappeared.
We'll find out what happened, in the next video.