How to skip lines of command into variable in Python

Question

I want to use the command:

subprocess.check_output(["powercfg", "-list"])

which gives me:

Existing Power Schemes (* Active)

-----------------------------------

Power Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (Balanced)

Power Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (High performance)

Power Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (Power saver) *

which is good. But, I only want the variables in the middle to go into their own variables without all the extra text. The problem is that the command comes out in multiple lines so I can't use (list[19:55]). I also need to do this with each of the strings inside the parentheses into their own variables but I think I can figure that out. I'm new to Python so I'm open to whatever.

well, split the lines that check_output returns and process them one by one. — Jean-François Fabre, Aug 05 '18 at 20:06
@Jean-FrançoisFabre Ok so I tried `list = subprocess.check_output(["powercfg", "-list"]).splitlines()` and it gave me all of it on one line and I don't know how I would extract the strings I need from that. — jangles, Aug 05 '18 at 20:18
Which parts do you want to extract? The xxx's or the text in the parenthesis? — aaldilai, Aug 05 '18 at 20:26
Okay so now I have `print(list.splitlines())` and each line is its own string. So how do I now use them each individually? — jangles, Aug 05 '18 at 20:43

score 0 · Accepted Answer · answered Aug 06 '18 at 02:03

Found the answer, even though my title is poorly worded I hope someone finds this because it was hell trying to figure it out. All you have to do is change the number at the end to go down lines:

firstplan = subprocess.check_output(["powercfg", "-list"], shell=True ).split('\n')[3]

secondplan = subprocess.check_output(["powercfg", "-list"], shell=True ).split('\n')[4]

etc.

I then went on to "parse" the ID strings out (if that's the right word) with this:

firstplanID = ((firstplan.split(": "))[1].split(" (")[0])

and then manually set a variable for each plan.

score 0 · Answer 2 · answered Aug 06 '18 at 02:11

you may try this:

data = '''Existing Power Schemes (* Active)

-----------------------------------

Power Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (Balanced)

Power Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (High performance)

Power Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (Power saver) *'''

values = [i.split()[3] for i in data.splitlines() if i.startswith('Power')]

the results:

>>> values
[
    'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx',
    'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx',
    'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
]

aaldilai · Answer 3 · 2018-08-07T01:46:01.973

You can try using regex.

import re

pattern = "Power Scheme GUID: ([a-z0-9]{8}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{12})\s+\(([a-zA-Z ]+)\)"
mystr = "Existing Power Schemes (* Active)\n-----------------------------------\nPower Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (Balanced)\nPower Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (High performance)\nPower Scheme GUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx  (Power saver) *"

re.findall(pattern, mystr)
# results: [('xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx', 'Balanced'), ('xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx', 'High performance'), ('xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx', 'Power saver')]

Given a string and a pattern, you can find all the parts of the string that match your pattern. In this case, I created a pattern, and grouped (using paranthesis) the id part and the type part. The result is a list of tuples. Each tuple is a pattern match.

How to skip lines of command into variable in Python

3 Answers3