python写文件指定路径 python文件路径操作

遍历文件

• 1 遍历文件并读取

• 1.1 用os.path.join连接
• 1.2 用加号连接
• 1.3 遍历文件夹和文件

• 2 只读取指定格式的文件
• 3 文件的其它操作

• 3.1 获取文件路径里的文件名、后缀名和所在的文件夹
• 3.2 获取文件夹下的文件夹的文件
• 3.3 获取文件夹下的所有文件和文件夹
• 3.4 得到当前python文件的执行绝对路径
• 3.5 获取当前时间和运行时间

• 4 复制一个文件到另一个文件

• 4.1 文件的裁剪与复制

• 5 判断文件是否存在和创建
• 6 os进行文件操作

1 遍历文件并读取

1.1 用os.path.join连接

# 遍历文件夹里面的所有文件
import os
path = r'G:\zhongxian\统计的图片'
filenames = os.listdir(path)
print(filenames)
print(len(filenames))
for filename in filenames:
	# 输出文件名
    print(filename)
    # 输出完整路径
    print(os.path.join(path, filename))

1.2 用加号连接

# 进行png图像3通道到单通道的转换
import os
import cv2

path_img = 'D:/schoolWork/yaoganDetect/dataset/target/SegmentationClassPNG/'
img_dir = os.listdir(path_img)
# 批量处理
for img_name in img_dir:
    img = cv2.imread(path_img + img_name)
    blue, green, red = cv2.split(img)
    save_path = "D:/schoolWork/yaoganDetect/presDataset/singlechaPNG/"+img_name
    cv2.imwrite(save_path, red)  # 写入图像

print("ok")

1.3 遍历文件夹和文件

2 只读取指定格式的文件

images = glob.glob(r'G:\XiaoMa\08OwnWork\zhongxian\语义分割数据\target\JPEGImages\*.jpg')

3 文件的其它操作

3.1 获取文件路径里的文件名、后缀名和所在的文件夹

# 获取文件名
dict_f['file_name'] = fname.split('/')[-1]

获取文件路径
images = r'G:\XiaoMa\08OwnWork\zhongxian\语义分割数据\target\JPEGImages\123.jpg'
kk = images.split("\\")[-1]
kk
s = images.replace(kk,'') # 删除即把对应字符替换为空
s

直接用os库
import os
img_path = r'E:\rs\2008\wenchuan_proj.tif'
os.path.dirname(img_path)
os.path.basename(img_path)

# 获取不带后缀的文件名和后缀名
import os

pathname = "../LR/ttnew/airplane1.tif"
basename = os.path.basename(pathname)
print("basename:"+basename)
splittext = os.path.splitext(basename)
print(splittext)

wenjianming = os.path.splitext(basename)[0]
houzhuiming = os.path.splitext(basename)[1]
print(wenjianming)
print(houzhuiming)

3.2 获取文件夹下的文件夹的文件

os.listdir()函数得到的是仅当前路径下的文件名，不包括子目录中的文件，所有需要使用递归的方法得到全部文件名。

直接给出代码，函数将返回类型为‘.jpeg’个文件名：

import os  
  
def listdir(path, list_name):  
    for file in os.listdir(path):  
        file_path = os.path.join(path, file)  
        if os.path.isdir(file_path):  
            listdir(file_path, list_name)  
        elif os.path.splitext(file_path)[1]=='.jpeg':  
            list_name.append(file_path)

3.3 获取文件夹下的所有文件和文件夹

import os  
  
def file_name(file_dir):   
    for root, dirs, files in os.walk(file_dir):  
        print(root) #当前目录路径  
        print(dirs) #当前路径下所有子目录  
        print(files) #当前路径下所有非目录子文件

3.4 得到当前python文件的执行绝对路径

python获取程序执行文件路径的方法(推荐)_python_脚本之家
https://www.jb51.net/article/138980.htm

import os
import sys
import time
dirname, filename = os.path.split(os.path.abspath(sys.argv[0]))   # 获取绝对路径并把文件夹和文件名拆开
print(dirname)  #  G:\XiaoMa\semiSupervise\AdversarialSemanticSegmentationKeras-master\xiaoma
print(filename)  # trrrr.py
print(os.path.realpath(sys.argv[0]))  # G:\XiaoMa\semiSupervise\AdversarialSemanticSegmentationKeras-master\xiaoma\trrrr.py
print(sys.argv[0])     # G:\XiaoMa\semiSupervise\AdversarialSemanticSegmentationKeras-master\xiaoma\trrrr.py
print(os.getcwd())  # G:\XiaoMa\semiSupervise\AdversarialSemanticSegmentationKeras-master\xiaoma
print(__file__)  # G:/XiaoMa/semiSupervise/AdversarialSemanticSegmentationKeras-master/xiaoma/trrrr.py

3.5 获取当前时间和运行时间

Python获取当前日期和日期差计算 - 云+社区 - 腾讯云
https://cloud.tencent.com/developer/article/1577646

import time
strtime = time.strftime('%Y-%m-%d %H:%M:%S',time.localtime())
print(strtime) # 2021-12-29 11:32:24

# 开始计时
time_start=time.time()
# 时间截止
time_end=time.time()
print('totally cost',time_end-time_start)

4 复制一个文件到另一个文件

def backup_file(path, path_two):
    """
    :param path:   路径1
    :param path_two: 路径2
    :return:
    """
    if os.path.isdir(path) and os.path.isdir(path_two):  # 判断传入的值为文件夹
        a = os.listdir(path)  # 读取该路径下的文件为列表
        for i in a:
            po = os.path.join(path, i)  # 路径1拼接
            po_two = os.path.join(path_two, i)  # 路径2拼接
            with open(po, "rb") as f:
                res_one = f.read()
                with open(po_two, "wb") as a:
                    a.write(res_one)
                    print("{}复制成功".format(i))
    else:
        print("不是文件夹")

4.1 文件的裁剪与复制

# 实现文件的裁剪和复制
import cv2 as cv
import os
import gdal
import numpy as np

def jian(jpg_path,jpg_to_path,png_path,png_to_path):
    """
    实现tif转jpg
    :param tif_path:输入路径
    :param jpg_path:输出路径
    :return:
    """
    filenames = os.listdir(jpg_path)
    print(filenames)
    print(len(filenames))
    index = np.random.permutation(len(filenames))
    filenames = np.array(filenames)[index].tolist()
    print(filenames)

    i = 0
    for filename in filenames:
        # 1 拷贝标签
        i += 1
        # 裁剪150个
        if i>150:
            break
        file_path = os.path.join(jpg_path, filename)
        jpg_to = os.path.join(jpg_to_path, filename)  # 路径2拼接
        with open(file_path, "rb") as f:
            res_one = f.read()
            with open(jpg_to, "wb") as a:
                a.write(res_one)

        # 拷贝标签
        filename_label = filename[:-4]+".png"
        file_png_path = os.path.join(png_path, filename_label)
        png_to = os.path.join(png_to_path, filename_label)  # 路径2拼接
        with open(file_png_path, "rb") as f:
            res_one = f.read()
            with open(png_to, "wb") as a:
                a.write(res_one)

        os.remove(file_path)
        os.remove(file_png_path)


def copy_file(jpg_path,jpg_to_path,png_path,png_to_path):
    filenames = os.listdir(jpg_path)
    print(filenames)
    print(len(filenames))
    index = np.random.permutation(len(filenames))
    filenames = np.array(filenames)[index].tolist()
    print(filenames)

    i = 0
    for filename in filenames:
        # 1 拷贝标签
        i += 1
        if i > 200:
            break
        file_path = os.path.join(jpg_path, filename)
        jpg_to = os.path.join(jpg_to_path, filename)  # 路径2拼接
        with open(file_path, "rb") as f:
            res_one = f.read()
            with open(jpg_to, "wb") as a:
                a.write(res_one)

        # 拷贝标签
        filename_label = filename[:-4] + ".png"
        file_png_path = os.path.join(png_path, filename_label)
        png_to = os.path.join(png_to_path, filename_label)  # 路径2拼接
        with open(file_png_path, "rb") as f:
            res_one = f.read()
            with open(png_to, "wb") as a:
                a.write(res_one)



if __name__ == '__main__':
    jian(
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\1train\1img",
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\2val\1img",
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\1train\2label",
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\2val\2label"
    )
    copy_file(
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\1train\1img",
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\2val\1img",
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\1train\2label",
        r"I:\5GF2\2biaozhu9jing20220107\3dataset\7datasetsuncangP_N\2val\2label"
    )

5 判断文件是否存在和创建

if not os.path.exists("./images"):
        os.makedirs("./images")

6 os进行文件操作

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