import re


def sep_chi_eng(text):
    """
    a function to separate adjacent Chinese and English words from each other with a space character
    e.g. sep_chi_eng("apple手機iphone") = "apple 手機 iphone"
    """
    text = re.sub("([a-z])([\u2E80-\u2FD5\u3400-\u4DBF\u4E00-\u9FCC])", "\\1 \\2", text)
    text = re.sub("([\u2E80-\u2FD5\u3400-\u4DBF\u4E00-\u9FCC])([a-z])", "\\1 \\2", text)
    return text