[Tutor] Closing triple quotation marks.

[Steven D'Aprano]

Lisi wrote:

> But I still can't write to the file.
> 
> If I do: 
> target.write(line1)
> 
> The value of the variable line1 is written to the file.  But if I put the 
> three variables into the write command, what gets printed is the name of the 
> variables, not their values.  I am clearly still doing something wrong. But I 
> can't see what.  I have even tried to see whether ''' gave a different result 
> from """, but it doesn't.  I have accepted KWrite's idea of what the white 
> space should be, and I have adapted it to all the variations I can think of.


What gets written is the string that is passed to write(). Anything 
inside quotation marks (single, or triple) is a string, not a variable. 
"line1" has nothing to do with the variable line1, it is merely the 
letters l i n e followed by digit 1. Python will never try to guess 
whether you mean a string "x" or a variable x. If it is inside quote 
marks, it is always a string.

There are a number of ways to write the contents of variables to a file. 
The best way depends on how many variables you have, and whether they 
are already strings or not. Here are a few:

# line1 etc. are already strings, and there are only a few of them:
target.write(line1 + '\n')  # add a newline after each string
target.write(line2 + '\n')
target.write(line3 + '\n')


# here's another way, using String Interpolation:
template = """
%s
%s
%s
"""
text = template % (line1, line2, line3)
# each %s inside the template is replaced with the contents
# of line1, line2 and line3 respectively
target.write(text)


# finally, if you have many lines, or a variable number of them:
lines = [line1, line2, line3]  # and possible more...
text = '\n'.join(lines)
target.write(text)



-- 
Steven