os.path解析檔案

不聞不若聞之，聞之不若見之，見之不若知之，知之不若行之。——荀子《儒效篇》

常用的解析檔案方法

os.path.splitext:分離檔案名與擴充名

def _parse_filename(filename):　　# 解析檔案名
    """Parse meta-information from given filename.

    Parameters
    ----------
    filename : str
        A VeRi image filename.

    Returns
    -------
    (int, int, str, str) | NoneType
        Returns a tuple with the following entries:

        * Unique ID of the individual in the image
        * Index of the camera which has observed the individual
        * Filename without extension
        * File extension

        Returns None if the given filename is not a valid filename.

    """
    filename_base, ext = os.path.splitext(filename)  #　分離檔案名與擴充名
    if '.' in filename_base:
        # Some images have double filename extensions.
        filename_base, ext = os.path.splitext(filename_base)
    if ext != ".jpg":
        return None
    vehicle_id, cam_num, frame_idx, detection_idx = filename_base.split('_')
    return int(vehicle_id), int(cam_num[1]), filename_base, ext
           

os.path.join:路徑拼接

os.path.join()函數：連接配接兩個或更多的路徑名元件,參數可以傳入多個路徑

1.如果各元件名首字母不包含’/’，則函數會自動加上

2.如果有一個元件是一個絕對路徑，則在它之前的所有元件均會被舍棄

3.如果最後一個元件為空，則生成的路徑以一個’/’分隔符結尾

import os

print("1:",os.path.join('aaaa','/bbbb','ccccc.txt'))

print("2:",os.path.join('/aaaa','/bbbb','/ccccc.txt'))

print("3:",os.path.join('aaaa','./bbb','ccccc.txt'))
           

output

1: /bbbb\ccccc.txt
2: /ccccc.txt
3: aaaa\./bbb\ccccc.txt