pythonは2つの絶対パスをつなぎ合わせます

#!/usr/bin/env python3
import os


def two_abs_join(abs1, abs2):
    """
                   ,
              （windows    C， D，E ... Linux   /root      /    ）
    :param abs1:       
    :param abs2:        
    :return:       
    """
    # 1.      （      \\    \）
    abs2 = os.fspath(abs2)

    # 2.        
    abs2 = os.path.splitdrive(abs2)[1]
    # 3.         
    abs2 = abs2.strip('\\/') or abs2
    return os.path.abspath(os.path.join(abs1, abs2))


user_home = r'E:\ftp\home\alex'
get_file_path = r"C:/a/alex.py"

t = two_abs_join(user_home, get_file_path)
print(t)


user_home = r'/user/path/alex/'
get_file_path = r"/root/alex.py"
t1 = two_abs_join(user_home, get_file_path)

print(t1)

E:\ftp\home\alex\a/alex.py
/user/path/alex/root/alex.py