Creating vaiables by looping though external text file line by line

Question

If i have a text file that contains an x number of lines like:

hostINFO = ['hostTYPE', 'hostOS', 'hostENV', 'hostNAME', 'hostIP', 'dbUNAME', 'dbPWD', 'dbPORT', 'orgNAME', 'nrdsTOKEN']

How would I create a python script that would:

import a line as a variable list so that i can refer to it as hostINFO[0] or hostINFO[1] etc....
execute the script against the variables
when completed go back to the host.txt file and get the next line and continue till no more lined exist.

update....

i changed my hosts.txt file format to be a comma delimited:

hostTYPE,hostOS,hostENV,hostNAME,hostIP,dbUNAME,dbPWD,dbPORT,orgNAME,nrdsTOKEN`

deploy.py

with open("hosts.txt") as f:
for line in f:
    hostINFO = line.strip().split(',')

Is the elements in ``hostInfo`` the lines of the file, or is each line in the file as ``hostINFO = [ .... ]`` ? — Thomas Fauskanger, Dec 24 '17 at 04:07
May I ask what your final goal is, i.e. what you are trying to achieve? — Thomas Fauskanger, Dec 24 '17 at 04:20
Take a look at this question on [eval and exec](https://stackoverflow.com/questions/2220699/whats-the-difference-between-eval-exec-and-compile-in-python) — Thomas Fauskanger, Dec 24 '17 at 04:27
i want to be able to update the host.txt file with new lines and have the python script execute against the new line. — rainman, Dec 24 '17 at 04:31
Check out my answer and see if it helps you. (But why don't just update the code files themselves instead of a separate text file?) — Thomas Fauskanger, Dec 24 '17 at 04:33
Maybe the [ConfigParser](https://docs.python.org/3/library/configparser.html#module-configparser) module to parse .ini-like files will suit your future needs? I guess it depends on the use case, though. — Thomas Fauskanger, Dec 24 '17 at 04:35

Thomas Fauskanger · Answer 1 · 2017-12-24T04:46:35.857

Be aware that evaluating or executing code from files is a serious vulnerability, and you should really be sure that you have control of what's in the file.

You can convert text file content into variables with something like:

with open('myfile.txt') as f:
    for line in f.readline():
        exec(line)
        first_element = hostINFO[0]    # hostTYPE
        second_element = hostINFO[1]   # hostOS
        # ...

See also Why should exec() and eval() be avoided?

score 0 · Answer 2 · answered Dec 24 '17 at 10:28

Why you are not using some regex recipe :

import re
pattern='\w+'

with open('hosts.txt','r') as f:
    for i in f:
        hostINFO=re.findall(pattern,i)
        print(hostINFO)
        print(hostINFO[0])
        print(hostINFO[1])
        #after exec complete it goes for next_line in file

output:

['hostINFO', 'hostTYPE', 'hostOS', 'hostENV', 'hostNAME', 'hostIP', 'dbUNAME', 'dbPWD', 'dbPORT', 'orgNAME', 'nrdsTOKEN']
hostINFO
hostTYPE

Creating vaiables by looping though external text file line by line

2 Answers2