fdisk -l has got to be one of the more common disk-related commands one might use while fussing about with raw disk images. The fdisk utility is ubiquitous across linux distributions (also brew install gptfdisk and brew cask install gdisk, supposedly). The -l argument provides a quick look raw sector & file system info. Figuring out the Start, End, Sectors, Size, Id, Format of a disk image's contents without needing to mount it and start lurking around is handy, just the sort of thing one might want to do with Python. Lets write a function to get these attributes into a dictionary- here's mine:

import subprocess
import re

def fdisk(image):

    #  `image`, a .img disk image:
    cmd = str('fdisk -l ' + image)

    # read fdisk output- everything `cmd` would otherwise print to your console on stdout
    # is instead piped into `proc`.
    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)

    # the raw stuff from stdout is not parseable as is, so we read into a string:
    result = proc.stdout.read().__str__()

    # figure out what type we should iterate with when looking via file / part contained within image.  I have no idea if anything besides .img will work- YMMV, but YOLO xD
    if '.iso' in result:
        iter = '.iso'
    if '.qcow2' in result:
        iter = '.qcow2'
        iter = '.img'

    # chop up fdisk results by file / partition-
    # the resulting `parts` are equivalent to fdisk "rows" in the shell
    parts = re.findall(r'' + iter + r'\d', result)

    # dictionary `disk` contains each "row" from `parts`:
    disk = {}
    for p in parts:
        # sub dictionary 'part' contains the handy fdisk output values:
        part = {}
        # get just the number words with regex sauce:
        line = result.split(p)[1]
        words = re.split(r'\s+', line)
        # place each word into 'part':
        part['Start'] = words[1]
        part['End'] = words[2]
        part['Sectors'] = words[3]
        part['Size'] = words[4]
        part['Id'] = words[5]
        part['Format'] = words[6].split('\\n')[0]
        # stick this part into 'disk', move onto next disk part:
        disk[p] = part
    return disk