import re

def str_split(input_str):
    return dict(zip(re.findall(r'\w+(?<!\\\\)=',input_str),re.split(r'\w+(?<!\\\\)=',input_str)[1:]))

if __name__ == '__main__':
    print(str_split('metadata=1.2 name=ston\\=e:su pershare UUID=eff4e7bc:47aea5cf:0f0560f0:2de38475'))