configfiles/bspwm/.config/scripts/barformatter.py

from sys import argv, exit

class DefaultDict(dict):
    def __init__(self,default):
        super(DefaultDict, self).__init__()
        self.default = default

    def __getitem__(self, key):
        return self.get(key, self.default)

if len(argv) <= 1:
    print("%s <format>" % argv[0])
    exit(1)

format_str = argv[1]
cache = DefaultDict("")

while True:
    print(format_str % cache)
    data = input().rstrip('\n').split(' ',1)
    if len(data) < 2:
        tag,content = data[0],""
    else:
        tag,content = data
    cache[tag] = content