Need to replace similar key values in a config file using python

Question

I need to replace values in a config file given below with some values that i will be getting from env variables . Below is the config file

vnv:
{
 endpoints: {
        directflow: {
            host = "http://xxxx.xxx.xyz.xxx.com/ver0.1/call/in.xml.gz";
        };
        incidents: {
            host = "http://xxxx.xxx.xyz.xxx.com/ver0.1/call/in.xml.gz";

        };
    };
    sleep = 30;
    timeout = 30;
};

i need to replace the host with values from environment variable. This file is not a json file. What approach should i take to substitute values here.

Why not use a regex? http://www.noah.org/wiki/RegEx_Python#URL_regex_pattern — jrd1, Apr 08 '20 at 16:32
What have you tried ? Can you parse the file to handle it in Python or can you just use the text content ? — azro, Apr 08 '20 at 16:33
https://stackoverflow.com/questions/4906977/how-to-access-environment-variable-values?rq=1 — azro, Apr 08 '20 at 16:35
CONFIG_FILE='file.cfg' with open(CONFIG_FILE, 'r') as file: filedata = file.read() — Shane Warne, Apr 08 '20 at 16:37
i will get the env variables using os module but how do i replace env value in my cfg file is the question i have — Shane Warne, Apr 08 '20 at 16:40
need to replace both the host entries with env1 and env2 . for example directflow: { host = "env1" and incidents: { host = "env2"; }; — Shane Warne, Apr 08 '20 at 17:10

kederrac · Answer 1 · 2020-04-08T16:58:42.810

2

you can use os.environ:

import os

host = os.environ.get('MY_ENV_HOST')

to replace in your file you can use:

import os
import re

with open('file.cfg') as fp:
    text = fp.read()

env_host = os.environ.get('MY_ENV_HOST')

host = f'http://{env_host}.com/'

new_text = re.sub(r'http://.*\.com/', host, text)

with open('file.cfg', 'w') as fp:
    fp.write(new_text)

edited Apr 08 '20 at 16:58

answered Apr 08 '20 at 16:32

kederrac

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Really need an answer for that ? There is dozen of duplicates ;) – azro Apr 08 '20 at 16:32
I just want to show an example, there are many ways and libraries to achieve this – kederrac Apr 08 '20 at 16:35

Need to replace similar key values in a config file using python

1 Answers1