Python 配置绝对路径和相对路径（为了解决文件夹内class文件调用别的文件夹内class的问题）

相对路径问题：

import os
import sys
# sys.path.append(os.getcwd())

# filename = "E:python小脚本测试导入projectsproject1project1_1Text1_1.txt" # 绝对路径
# filename = "E:python小脚本测试导入projectsproject1project1_1Text1_1.txt" # 绝对路径

# filename = "Text1_1.txt"  # 当前目录
# filename = "/python小脚本/测试导入/projects/project1/project1_1/Text1_1.txt" # 根目录
# filename = "../测试导入/projects/project1/project1_1/Text1_1.txt" # 上级目录
# filename = "project1_1/Text1_1.txt" # 上级目录
# filename = "../../测试导入/projects/project1/project1_1/Text1_1.txt" # 上级目录的上级目录
# filename = "../../../测试导入/projects/project1/project1_1/Text1_1.txt" # 上级目录的上级目录的上级目录
# filename = "project1_1/Text1_1.txt" # 当前目录下的子目录
filename = "./project1_1/Text1_1.txt" # 当前目录下的子目录，同上

print("当前路径:")
print(os.getcwd())
print()

with open (filename, encoding="utf-8") as file_object:
    for line in file_object:
        print(line.strip())