day9: path processing (os module)

Disclaimer: This article is a blogger original article, follow the CC 4.0 BY-SA copyright agreement, reproduced, please attach the original source link and this statement.

This link: https://blog.csdn.net/weixin_43264177/article/details/102763519

Third, the path processing
python inside the os module There are many ways we achieve through the code to create, delete, and change directories, specifically listed below:
1. memorize: os.path.dirname and os.path.join
2. The following methods can be (uses look for information)
magic variables: file and name
file : absolute path of all files
name : where the module (file) module name, (if, then the value of the program startup file __main__)

"""
通过文件的路径去打开文件
相对路径：相对当前的工作路径去定位文件位置
     .:代表当前路径
     ..:代表上一级路径（父级路径）
绝对路径：相对于电脑的根目录来进行定位（windows下面就是根据盘符）

"""

# @time:2019/10/27 5:47
# @Author:coco
# @File:test_path.py
# @software:PyCharm

with open('py21_01day_01file.py','r',encoding='utf8') as f:
    data=f.read()
    print(data)

The result: Path not found error

# 相对路径
with open('./py23_01day_01file.py','r',encoding='utf8') as f:
    data=f.read()
    print(data)

The result: open the file, make py23_01day_01file.py this file in the directory day9 directory

# 绝对路径
with open('D:\Python_test\py23_class\py23_04day\zy_03day.py', 'r', encoding='utf8') as f:
    data = f.read()
    print(data)

operation result:

# @time:2019/10/27 6:17
# @Author:coco
# @File:os_path_test.py
# @software:PyCharm

import os

# dirname()可以获取文件的父级路径
f_path="D:\Python_test\py23_class\py23_04day\zy_03day.py"
res=os.path.dirname(f_path)
print("os.path.dirname使用（res）:")
print(res)

# 魔法变量
# __file___:代表当前文件在电脑中的绝对路径
print("魔法变量__file__:")
print(__file__)

# os.path.dirname:获取路径的父级目录

res1=os.path.dirname(__file__)
print("获取父级目录（res1）:")
print(os.path.dirname(res1))

# 获取项目目录的文件
res2=os.path.dirname(__file__)
base_dir=os.path.dirname(res2)
print("获取项目目录的文件（base_dir）:")
print(base_dir)

# 在电脑中的绝对路径
f2=base_dir+'\\'+'py23_04day'+'\\'+'zy_03day.py'
print("在电脑中的绝对路径（f2）:")
print(f2)

# os.path.join:做路径拼接
file_path=os.path.join(base_dir,'py23_04day','zy_03day.py')
print("os.path.join使用，利用拼接的方式（file_path）:")
print(file_path)

operation result:

# @time:2019/10/27 6:42
# @Author:coco
# @File:os_path_other.py
# @software:PyCharm

"""
os模块
"""

import os
# 查看当前工作路径
print('查看当前工作路径:')
print(os.getcwd())

# 切换工作路径到父级路径
os.chdir('..')
print('切换工作路径到父级路径:')
print(os.getcwd())

# 又切换回来了
os.chdir('路径处理')
print('又切换工到原来的路径:')
print(os.getcwd())

# 获取当前工作目录下所有的文件和目录
print('获取当前工作目录下所有的文件和目录:')
print(os.listdir())

# 获取了当前文件下所有的文件
os.chdir('../../py23_02day')
print('获取了当前文件下所有的文件:')
print(os.listdir())

# 创建文件夹
# os.mkdir('python778')

# 删除文件夹
# os.rmdir('python666')

# 判断是否是文件
res=os.path.isfile('D:\Python_test\py23_class\py23_04day\zy_03day.py')
print(res)

# 判断是否是目录
res1=os.path.isdir('D:\Python_test\py23_class\py23_04day\zy_03day.py')
print(res1)

operation result: