Battery charge script (modified from http://stevelosh.com/blog/2010/02/my-extravagant-zsh-prompt/)

batterycharge.py

#!/usr/bin/env python
# coding=UTF-8

import argparse
import math
import subprocess
import sys

def main(argv):
    parser = argparse.ArgumentParser(description='Display current battery capacity')
    parser.add_argument('-c', '--color', action='store_true')
    parser.add_argument('-s', '--slots', default=10)
    args = parser.parse_args()
    
    p = subprocess.Popen(["ioreg", "-rc", "AppleSmartBattery"], stdout=subprocess.PIPE)
    output = p.communicate()[0]
    
    total_slots = int(args.slots)
    
    o_max = [l for l in output.splitlines() if 'MaxCapacity' in l][0]
    o_cur = [l for l in output.splitlines() if 'CurrentCapacity' in l][0]
    
    b_max = float(o_max.rpartition('=')[-1].strip())
    b_cur = float(o_cur.rpartition('=')[-1].strip())
    
    charge = b_cur / b_max
    charge_threshold = int(math.ceil(float(total_slots) * charge))
    
    slots = []
    filled = int(math.ceil(charge_threshold * (float(total_slots) / 8.0))) * u'•'
    empty = (total_slots - len(filled)) * u'▹'
    
    out = (filled + empty).encode('utf-8')
    
    if args.color is True:
        color_green = '%{%}'
        color_yellow = '%{%}'
        color_red = '%{%}'
        color_reset = '%{%}'
        color_out = (
            color_green if len(filled) > 6
            else color_yellow if len(filled) > 4
            else color_red
        )
        out = color_out + out + color_reset
    
    sys.stdout.write(out)

if __name__ == "__main__":
    main(sys.argv[1:])