I am trying to use this command:

import subprocess
a = 'foo'
result = subprocess.check_output(["cal | awk '{ gsub($1, $a); print $cal}'", "-l"], 
                                 shell=True)

My intention is to change the first column of the cal variable with my own variable, a already has the same type as $1, but I'm struggling to print a new calendar with my own entries in certain places.

If this is a bad idea, I'm looking at how to change certain days to some other characters in the cal command.

CodePudding user response：

Not exactly sure where do you want to print that new calendar but I found few problems with your shell command

1. Variables inside ' ' doesn't evaluate. You need to use " "
2. I guess you expect to take a from python script, not shell env variable. To populate it you can use f-strings.
3. To replace string in text, I would rather use sed.

Solution:

import subprocess

python_var = "foo"
result = subprocess.check_output(f'cal | sed "s/$shell_var/{python_var}/"', shell=True)
print(result)

$ export shell_var=mo
$ python script.py # it prints new result variable that contains new calendar.