Python Forum - how to remove \n from file?

This python code writing configuration file for getmail to retrieve the mail, in the first and last f.write code i use the "\n" to break the lines for new line:

cur  = conn.cursor() 
query = "SELECT user, passwd, server FROM pop"
cur.execute(query)
for idx, row in enumerate(cur, start=1):
	with open(f'mail{idx}', 'w') as f:
		
		f.write('[options]\n verbose = 1\n read_all = false\n delete = true\n received = false\n delivered_to = false\n message_log = /home/mail/log\n message_log_verbose = true\n ')
		f.write('username = ')
		f.write(row[0])
		f.write("\n")
		f.write(' password = ')
		f.write(row[1])
		f.write("\n")
		f.write(' server = ')
		f.write(row[2])
		f.write("\n")
		f.write('[destination]\n type = MDA_external\n path = /usr/bin/exim\n arguments = ("-i", "-bm", "user@localhost")\n unixfrom = true\n ')

with cat the file seem ok there is no '\n' in the end of lines, but when run the getmail get the error:

Configuration error: configuration file /home/mail/mail1 incorrect (File contains parsing errors: /home/mail/mail1
	[line  2]: ' verbose = 1\n'
	[line  3]: ' read_all = false\n'
	[line  4]: ' delete = true\n'
	[line  5]: ' received = false\n'
	[line  6]: ' delivered_to = false\n'

how to remove the '\n' from the end of lines.

If you remove the newline, they won't be separate lines.

I suspect the error is telling you that you have whitespace at the beginning of the lines. For getmail, the configuration assumes that if it starts with whitespace it is a continuation of the previous line.

Quote:A parameter value, if necessary, can span multiple lines. To indicate that the second and subsequent lines form a continuation of the previous line, they need to begin with leading whitespace, like this:
first_parameter = value
    first parameter value continues here
second_parameter = value

Get rid of the leading whitespace.

instead of writing the file like you do, look at configparser module from standard library. Your code will be way more clean and readable

import configparser

my_config="""[options]
verbose = 1
read_all = false
delete = true
received = false
delivered_to = false
message_log = /home/mail/log
message_log_verbose = true

[destination]
type = MDA_external
path = /usr/bin/exim
arguments = ("-i", "-bm", "user@localhost")
unixfrom = true"""

config = configparser.ConfigParser()
config.read_string(my_config)

cur  = conn.cursor() 
query = "SELECT user, passwd, server FROM pop"
cur.execute(query)
for idx, row in enumerate(cur, start=1):
    credentials = dict(zip(('username', 'password', 'server'), row))
    config['options'].update(credentials)
    with open(f'mail{idx}', 'w') as f:
        config.write(f)

instead of string my_config can be a dict

Also I don't know if MariaDB python connector supports DictCursor like MySQL connector, but if it does - you can use it.

Thanks for replies, yes also the problem was with the white spaces after \n i remove the all spaces after \n now it working, also special thanks to buran for the perfect code, it is working nice, the only thing is i forgot to add two lines (one section), i tried to add these lines to the code but failed, can you please add these two lines to the code so the configuration file just look like this:

[options]
verbose = 1
read_all = false
delete = true
received = false
delivered_to = false
message_log = /home/mail/log
message_log_verbose = true

[retriever]
type = SimplePOP3Retriever
username = [email protected]
password = ******
server = pop.gmail.com

[destination]
type = MDA_external
path = /usr/bin/exim
arguments = ("-i", "-bm", "user@localhost")
unixfrom = true

(Feb-04-2021, 07:00 AM)shams Wrote: [ -> ]i tried to add these lines to the code but failed

C'mon, it couldn't be that difficult. Show what have you tried

i added the lines as this:

my_config="""[options]
verbose = 1
read_all = false
delete = true
received = false
delivered_to = false
message_log = /home/mail/log
message_log_verbose = true

[retriever]
type = SimplePOP3Retriever
 
[destination]
type = MDA_external
path = /usr/bin/exim
arguments = ("-i", "-bm", "user@localhost")
unixfrom = true"""
 
config = configparser.ConfigParser()
config.read_string(my_config)
 
cur  = conn.cursor() 
query = "SELECT user, passwd, server FROM pop"
cur.execute(query)
for idx, row in enumerate(cur, start=1):
    credentials = dict(zip(('username', 'password', 'server'), row))
    config['options'].update(credentials)
    with open(f'mail{idx}', 'w') as f:
        config.write(f)

and this was the output:

[options]
verbose = 1
read_all = false
delete = true
received = false
delivered_to = false
message_log = /home/mail/log
message_log_verbose = true
username = [email protected]
password = ******
server = pop.gmail.com

[retriever]
type = SimplePOP3Retriever

[destination]
type = MDA_external
path = /usr/bin/exim
arguments = ("-i", "-bm", "user@localhost")
unixfrom = true

i changed the double quotes to the deferent positions but no luck.

look at line 27. You need to update that too, to update retriever section, not options.

Thanks for the help i just changed to update the retriever instead of option, now every thing is going ok.