【Python杂项】os.path.join()函数用法详解

Python_os.path.join()函数用法详解

os.path.join()函数：连接两个或更多的路径名组件

• 如果各组件名首字母不包含’/’，则函数会自动加上

• 如果有一个组件是一个绝对路径，则在它之前的所有组件均会被舍弃

• 如果最后一个组件为空，则生成的路径以一个’/’分隔符结尾

Demo1

import os

Path1 = 'home'
Path2 = 'develop'
Path3 = 'code'

Path10 = Path1 + Path2 + Path3
Path20 = os.path.join(Path1,Path2,Path3)
print ('Path10 = ',Path10)
print ('Path20 = ',Path20)

输出

Path10 = homedevelopcode
Path20 = home\develop\code

Demo2

import os

Path1 = '/home'
Path2 = 'develop'
Path3 = 'code'

Path10 = Path1 + Path2 + Path3
Path20 = os.path.join(Path1,Path2,Path3)
print ('Path10 = ',Path10)
print ('Path20 = ',Path20) 

输出

Path10 = /homedevelopcode
Path20 = /home\develop\code

Demo3

import os

Path1 = 'home'
Path2 = '/develop'
Path3 = 'code'

Path10 = Path1 + Path2 + Path3
Path20 = os.path.join(Path1,Path2,Path3)
print ('Path10 = ',Path10)
print ('Path20 = ',Path20) 

输出

Path10 = home/developcode
Path20 = /develop\code

Demo4

import os

Path1 = 'home'
Path2 = 'develop'
Path3 = '/code'

Path10 = Path1 + Path2 + Path3
Path20 = os.path.join(Path1,Path2,Path3)
print ('Path10 = ',Path10)
print ('Path20 = ',Path20 )

输出

Path10 = homedevelop/code
Path20 = /code

实际应用

video_path = "./data/testvideo1.mp4"
label_path = "./data/labels"
file_name = "testvideo1"

label_file_path = os.path.join(label_path, file_name + "_" + str(frame_counter) + ".txt")