[SOLVED] Linefeed when writing "f" strings to text file?

[Winfried]

Hello,

I don't know how those strings are called in Python.

In the second block, I can't get linefeeds: The two strings are on a single line. What's the correct syntax?

#OK
with open("test.txt", 'w',encoding='utf-8') as writer:
	writer.write("line1")
	writer.write("line2\r\n")
	writer.write("line3\n")
	writer.write("line4")

#NOK
#with open(f"{TITLE}.cmd", 'wt',encoding='utf-8') as writer:
with open(f"{TITLE}.cmd", 'w',encoding='utf-8') as writer:
	writer.write(fr"c:\test -f 139 {URL}\\n")
	writer.write(fr"c:\test -f 92 {URL}\\n")

Thank you.

---
Edit: Makes no difference:

with open(f"{FILE}.cmd", 'wt',encoding='utf-8') as writer:
	writer.write(f"{TITLE}\n")
	writer.flush()
	writer.write(fr"c:\blah -o audio.m4a -f 139 {URL}\\n")
	writer.flush()

[Pedroski55]

Not too sure exactly what you are trying to achieve. Maybe use print()?

title = '/home/peterr/temp/TITLE'
url = '123.456.789.123'
with open(f"{title}.cmd", 'w') as writer:
    print(fr"c:\test -f 139 {url}", file=writer)
    print(fr"c:\test -f 92 {url}", file=writer)

[Winfried]

Just writing to a file.

Isn't this the right way to do it?

with open("blah.txt", 'wt',encoding='utf-8') as writer:
	writer.write("line1")
	writer.write("line2")

---
Edit: The problem occurs specifically when using the "fr" setting:

TITLE = "blah"
URL = "blah2"
with open('readme.txt', 'w') as f:
	#BAD
	f.write(fr"c:\blah -o audio.m4a -f 139 {URL}\\n")
	#BAD
	f.write(fr"c:\blah -o audio.m4a -f 139 {URL}\n")
	f.write(f"{TITLE}\n")
	f.write('line1\n')
	f.write('line2\n')

---
Edit: A work-around is to simply use forward slashes. Windows is fine with that syntax:

with open(f"{FILE}.cmd", 'wt',encoding='utf-8') as writer:
	writer.write(f"c:/blah -o audio.m4a -f 139 {URL}\n")

[Larz60+]

Best to show the complete runnable module, or at least enough so that the code can be run and tested by us.

It looks as though you are trying to make it too complicated.

take a look at Python 3 Module of the Week

specifically The File System

It will get you going in the right direction.

[Winfried]

Thanks for the links.

Here's a snippet that shows the problem:

FILE = "blah"
with open(f"{FILE}.cmd", 'wt',encoding='utf-8') as writer:
	writer.write(f"REM {FILE}\n")

	#r prefix to use back slashes instead of forward slashes
	#no newline
	writer.write(rf"c:\{FILE}.exe dummy\n")

	writer.write("dummy")

[buran]

The problem is not being able to use new-line \n inside raw string. So two possible solutions:

FILE = "blah"
with open(f"{FILE}.txt", 'wt',encoding='utf-8') as writer:
    writer.write(f"REM {FILE}\n")
    writer.write((rf"c:\{FILE}.exe dummy" "\n")) # use brackets to concatenate 2 string literals
    writer.write("dummy")

or

FILE = "blah"
NEWLINE='\n' # define a constant for later use inside the f-string
with open(f"{FILE}.txt", 'wt',encoding='utf-8') as writer:
    writer.write(f"REM {FILE}\n")
    writer.write(rf"c:\{FILE}.exe dummy{NEWLINE}")
    writer.write("dummy")

credit: https://stackoverflow.com/q/14974222/4046632

That said, you may prefer different approach to writing windows path, not using raw string