遍历文件夹下的文件（txt）并删除最后一行

labelimg打标 最后一个标 不想要了
而yolo格式下 所有标注 如下
0 0.554861 0.434375 0.031944 0.020313
1 0.549306 0.488281 0.020833 0.017188
2 0.502778 0.432031 0.022222 0.017188
3 0.550000 0.405469 0.022222 0.014063
4 0.602778 0.435937 0.019444 0.023438

写脚本 仅保留前4行
使用网上各种程序进行裁缝
先创建个两个文件夹：把所有原txt文档放在labels_old下，labels_new为空文件夹

import os, shutil,re
if __name__=='__main__':
    work_dir = 'F:\lianxi\yolo\test\1160_10点\xya1b1c1\labels_old\'
    new_dir = 'F:\lianxi\yolo\test\1160_10点\xya1b1c1\labels_new\'
    for parent, dirnames, filenames in os.walk(work_dir,  followlinks=True):
        for filename in filenames:
            file_path = os.path.join(parent, filename)
            print('file_path:'+file_path)#file_path为path:原文件加下包含文件名.txt
            print('parent:' + parent)#parent为原文件夹path
            print('filename:' + filename)#filename为原文件名
            print('')
            file = open(file_path,"r+",encoding='UTF-8')
            newFile = open(new_dir+filename,"w",encoding='UTF-8')
            print('new_dir+filename:' + new_dir+filename)  # new_dir+filename为新文件路径

            flag=-1
            for line in file.readlines(): #遍历每行
                # print('line:'+line)
                flag = flag + 1
                if ( flag == 4):
                    
                    break
                print('line:'+line)

                newFile.writelines(line)
           
            print (filename)
            print('——'*100)
            newFile.close()
            file.close()

运行结果
file_path:F:lianxiyolotest1160_10点xya1b1c1labels_old330bei.txt
parent:F:lianxiyolotest1160_10点xya1b1c1labels_old
filename:330bei.txt

new_dir+filename:F:lianxiyolotest1160_10点xya1b1c1labels_new330bei.txt
line:0 0.554861 0.434375 0.031944 0.020313

line:1 0.549306 0.488281 0.020833 0.017188

line:2 0.502778 0.432031 0.022222 0.017188

line:3 0.550000 0.405469 0.022222 0.014063

330bei.txt

file_path:F:lianxiyolotest1160_10点xya1b1c1labels_old331bei.txt
parent:F:lianxiyolotest1160_10点xya1b1c1labels_old
filename:331bei.txt

new_dir+filename:F:lianxiyolotest1160_10点xya1b1c1labels_new331bei.txt
line:0 0.556250 0.441797 0.029167 0.019531

line:1 0.552778 0.490625 0.022222 0.014063

line:2 0.502778 0.437500 0.016667 0.015625

line:3 0.550694 0.412109 0.020833 0.013281

331bei.txt

file_path:F:lianxiyolotest1160_10点xya1b1c1labels_old332bei.txt
parent:F:lianxiyolotest1160_10点xya1b1c1labels_old
filename:332bei.txt

new_dir+filename:F:lianxiyolotest1160_10点xya1b1c1labels_new332bei.txt
line:0 0.564583 0.448047 0.023611 0.016406

line:1 0.556944 0.500781 0.027778 0.012500

line:2 0.513889 0.446484 0.025000 0.016406

line:3 0.559028 0.420312 0.023611 0.012500

332bei.txt

再贴一个找到的 单独删除某个文件的 第几行 和倒数第几行

import os

def delete_lines(filename, head,tail):
    fin = open(filename, 'r')
    a = fin.readlines()
    fout = open(filename, 'w')
    b = ''.join(a[head:-tail])
    fout.write(b)

file = r'F:lianxiyolotest1160_10点xya1b1a.txt'

delete_lines(file,6,1) #删除第6行 和倒数第1行

修改后：删除最后一行：

import os

def delete_lines(filename, tail):
    fin = open(filename, 'r')
    a = fin.readlines()
    fout = open(filename, 'w')
    b = ''.join(a[:-tail])
    fout.write(b)

file = r'F:lianxiyolotest1160_10点xya1b1a.txt' #F:lianxiyolotest1160_10点xya1b1a.txt
delete_lines(file,1)