From 6077af8bf52631c52e02ac8ce82b0c4cc7ef0818 Mon Sep 17 00:00:00 2001
From: "2563491540@qq.com" <2563491540@qq.com>
Date: Tue, 24 Jan 2023 15:57:10 +0800
Subject: [PATCH 1/2] modified medpy_third_lib.ipynb

---
 medpy_third_lib.ipynb | 314 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 274 insertions(+), 40 deletions(-)

diff --git a/medpy_third_lib.ipynb b/medpy_third_lib.ipynb
index 53f599f..9863f9d 100644
--- a/medpy_third_lib.ipynb
+++ b/medpy_third_lib.ipynb
@@ -3,8 +3,13 @@
   {
    "cell_type": "code",
    "execution_count": 3,
-   "id": "c69a7351",
-   "metadata": {},
+   "id": "5432afd4",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [],
    "source": [
     "# !pip install medpy matplotlib #-i http://mirrors.aliyun.com/pypi/simple/ --trusted-host mirrors.aliyun.com"
@@ -12,10 +17,56 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
-   "id": "164df929",
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 1,
+   "id": "9ba6598a",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Looking in indexes: https://mirrors.bfsu.edu.cn/pypi/web/simple/\n",
+      "\u001b[33mWARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.HTTPSConnection object at 0x7f3beef45450>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution')': /pypi/web/simple/medpy/\u001b[0m\n",
+      "Collecting medpy\n",
+      "  Downloading https://mirrors.bfsu.edu.cn/pypi/web/packages/3b/70/c1fd5dd60242eee81774696ea7ba4caafac2bad8f028bba94b1af83777d7/MedPy-0.4.0.tar.gz (151 kB)\n",
+      "\u001b[K     |████████████████████████████████| 151 kB 980 kB/s eta 0:00:01\n",
+      "\u001b[?25hCollecting matplotlib\n",
+      "  Downloading https://mirrors.bfsu.edu.cn/pypi/web/packages/ad/62/7b662284352867a86acfb636761ba351723fc3a235efd8397578d903413d/matplotlib-3.5.3-cp37-cp37m-manylinux_2_5_x86_64.manylinux1_x86_64.whl (11.2 MB)\n",
+      "\u001b[K     |████████████████████████████████| 11.2 MB 5.7 MB/s eta 0:00:01\n",
+      "\u001b[?25hRequirement already satisfied: numpy>=1.17 in /opt/conda/lib/python3.7/site-packages (from matplotlib) (1.21.2)\n",
+      "Requirement already satisfied: pyparsing>=2.2.1 in /opt/conda/lib/python3.7/site-packages (from matplotlib) (3.0.8)\n",
+      "Requirement already satisfied: packaging>=20.0 in /opt/conda/lib/python3.7/site-packages (from matplotlib) (21.3)\n",
+      "Requirement already satisfied: pillow>=6.2.0 in /opt/conda/lib/python3.7/site-packages (from matplotlib) (8.4.0)\n",
+      "Collecting cycler>=0.10\n",
+      "  Downloading https://mirrors.bfsu.edu.cn/pypi/web/packages/5c/f9/695d6bedebd747e5eb0fe8fad57b72fdf25411273a39791cde838d5a8f51/cycler-0.11.0-py3-none-any.whl (6.4 kB)\n",
+      "Requirement already satisfied: python-dateutil>=2.7 in /opt/conda/lib/python3.7/site-packages (from matplotlib) (2.8.2)\n",
+      "Collecting fonttools>=4.22.0\n",
+      "  Downloading https://mirrors.bfsu.edu.cn/pypi/web/packages/e3/d9/e9bae85e84737e76ebbcbea13607236da0c0699baed0ae4f1151b728a608/fonttools-4.38.0-py3-none-any.whl (965 kB)\n",
+      "\u001b[K     |████████████████████████████████| 965 kB 66.1 MB/s eta 0:00:01\n",
+      "\u001b[?25hCollecting kiwisolver>=1.0.1\n",
+      "  Downloading https://mirrors.bfsu.edu.cn/pypi/web/packages/ab/8f/8dbe2d4efc4c0b08ec67d6efb7cc31fbfd688c80afad85f65980633b0d37/kiwisolver-1.4.4-cp37-cp37m-manylinux_2_5_x86_64.manylinux1_x86_64.whl (1.1 MB)\n",
+      "\u001b[K     |████████████████████████████████| 1.1 MB 46.1 MB/s eta 0:00:01\n",
+      "\u001b[?25hRequirement already satisfied: typing-extensions in /opt/conda/lib/python3.7/site-packages (from kiwisolver>=1.0.1->matplotlib) (3.10.0.2)\n",
+      "Requirement already satisfied: six>=1.5 in /opt/conda/lib/python3.7/site-packages (from python-dateutil>=2.7->matplotlib) (1.16.0)\n",
+      "Requirement already satisfied: scipy>=1.1.0 in /opt/conda/lib/python3.7/site-packages (from medpy) (1.7.3)\n",
+      "Collecting SimpleITK>=1.1.0\n",
+      "  Downloading https://mirrors.bfsu.edu.cn/pypi/web/packages/72/aa/aa10190bed1ee3f3b237b52cac7761c713f92d10aedaced13d7ad457b9de/SimpleITK-2.2.0-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (52.8 MB)\n",
+      "\u001b[K     |████████████████████████████████| 52.8 MB 9.4 MB/s eta 0:00:011     |███████████████▏                | 25.0 MB 5.1 MB/s eta 0:00:06     |███████████████▌                | 25.6 MB 5.1 MB/s eta 0:00:06     |███████████████████▏            | 31.7 MB 6.7 MB/s eta 0:00:04\n",
+      "\u001b[?25hBuilding wheels for collected packages: medpy\n",
+      "  Building wheel for medpy (setup.py) ... \u001b[?25ldone\n",
+      "\u001b[?25h  Created wheel for medpy: filename=MedPy-0.4.0-py3-none-any.whl size=214963 sha256=5a0acd8c11ca7a35a43bf6f8c56f1e0286798819c6e17dd5d6c91b3fa0c8102d\n",
+      "  Stored in directory: /root/.cache/pip/wheels/e0/8e/5b/45329e6ddb95c2aff4dcafebddbf6f22243425fbe383475c23\n",
+      "Successfully built medpy\n",
+      "Installing collected packages: SimpleITK, kiwisolver, fonttools, cycler, medpy, matplotlib\n",
+      "Successfully installed SimpleITK-2.2.0 cycler-0.11.0 fonttools-4.38.0 kiwisolver-1.4.4 matplotlib-3.5.3 medpy-0.4.0\n"
+     ]
+    }
+   ],
    "source": [
     "# !pip install medpy matplotlib -i https://mirrors.bfsu.edu.cn/pypi/web/simple/"
    ]
@@ -23,8 +74,13 @@
   {
    "cell_type": "code",
    "execution_count": 5,
-   "id": "53d8184b",
-   "metadata": {},
+   "id": "9357f424",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [],
    "source": [
     "import os\n",
@@ -35,8 +91,13 @@
   {
    "cell_type": "code",
    "execution_count": 6,
-   "id": "7cb13c83",
-   "metadata": {},
+   "id": "1e5107e6",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [],
    "source": [
     "# 文件夹路径和文件名\n",
@@ -53,8 +114,13 @@
   {
    "cell_type": "code",
    "execution_count": 5,
-   "id": "1f5f1dcd",
-   "metadata": {},
+   "id": "2022b7f8",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -73,8 +139,13 @@
   {
    "cell_type": "code",
    "execution_count": 6,
-   "id": "01d66613",
-   "metadata": {},
+   "id": "b2f08842",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "data": {
@@ -107,8 +178,13 @@
   {
    "cell_type": "code",
    "execution_count": 7,
-   "id": "76fefbc2",
-   "metadata": {},
+   "id": "59d3ffae",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "data": {
@@ -144,8 +220,13 @@
   {
    "cell_type": "code",
    "execution_count": 8,
-   "id": "aab13d4b",
-   "metadata": {},
+   "id": "c07f3c80",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [],
    "source": [
     "# 设置数组形状为10000*10000的元组\n",
@@ -155,8 +236,13 @@
   {
    "cell_type": "code",
    "execution_count": 9,
-   "id": "f32f2ab3",
-   "metadata": {},
+   "id": "66571f08",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -191,8 +277,13 @@
   {
    "cell_type": "code",
    "execution_count": 10,
-   "id": "ef4058cf",
-   "metadata": {},
+   "id": "23cf3200",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -229,8 +320,13 @@
   {
    "cell_type": "code",
    "execution_count": 11,
-   "id": "4fa3d6d7",
-   "metadata": {},
+   "id": "728772d9",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -267,8 +363,13 @@
   {
    "cell_type": "code",
    "execution_count": 12,
-   "id": "1ced0ce4",
-   "metadata": {},
+   "id": "e9fbe52d",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -306,8 +407,13 @@
   {
    "cell_type": "code",
    "execution_count": 13,
-   "id": "9eab87fc",
-   "metadata": {},
+   "id": "b4b4b8be",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -344,8 +450,13 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "id": "11363f8f",
-   "metadata": {},
+   "id": "1e086f36",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [],
    "source": [
     "%%timeit\n",
@@ -366,8 +477,13 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "id": "219c7293",
-   "metadata": {},
+   "id": "9d3fa972",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -404,8 +520,13 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "id": "6dac370a",
-   "metadata": {},
+   "id": "aee7d9b7",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -442,8 +563,13 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "id": "86ec96bb",
-   "metadata": {},
+   "id": "a9bce405",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -480,8 +606,13 @@
   {
    "cell_type": "code",
    "execution_count": 5,
-   "id": "d359c642",
-   "metadata": {},
+   "id": "1ecd14f6",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -518,8 +649,13 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "id": "dc54ca8a",
-   "metadata": {},
+   "id": "4244b8a2",
+   "metadata": {
+    "collapsed": true,
+    "jupyter": {
+     "outputs_hidden": true
+    }
+   },
    "outputs": [
     {
      "name": "stdout",
@@ -552,6 +688,104 @@
     "specifity=true_negative_rate(predict,ground_truth)\n",
     "print(\"特异度/真阴性率为{}\".format(specifity))"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "53e473f5",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "%%timeit\n",
+    "from medpy.metric.binary import true_positive_rate\n",
+    "import jax.numpy as numpy\n",
+    "from jax import random\n",
+    "# 设置伪随机数种子\n",
+    "rng1=random.PRNGKey(1)\n",
+    "rng2=random.PRNGKey(2)\n",
+    "# 定义预测结果和真实标记数组\n",
+    "predict=random.randint(key=rng1,shape=(50,50),minval=0,maxval=4)\n",
+    "ground_truth=random.randint(key=rng2,shape=(50,50),minval=0,maxval=4)\n",
+    "# 计算特异度/真阴性率\n",
+    "specifity=true_negative_rate(predict,ground_truth)\n",
+    "print(\"特异度/真阴性率为{}\".format(specifity))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 12,
+   "id": "d29984ea",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "4.24 ms ± 1.01 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)\n"
+     ]
+    }
+   ],
+   "source": [
+    "%%timeit\n",
+    "from medpy.metric.binary import precision\n",
+    "import jax.numpy as numpy\n",
+    "from jax import random\n",
+    "# 设置伪随机数种子\n",
+    "rng1=random.PRNGKey(1)\n",
+    "rng2=random.PRNGKey(2)\n",
+    "# 定义预测结果和真实标记数组\n",
+    "predict=random.randint(key=rng1,shape=(50,50),minval=0,maxval=4)\n",
+    "ground_truth=random.randint(key=rng2,shape=(50,50),minval=0,maxval=4)\n",
+    "# 计算精确度/阳性预测值\n",
+    "Precision=precision(predict,ground_truth)\n",
+    "print(\"精确度/阳性预测值为{}\".format(Precision))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "3c2c4d4a",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "精确度/阳性预测值为0.7548283261802575\n",
+      "2.97 ms ± 255 µs per loop (mean ± std. dev. of 7 runs, 1 loop each)\n"
+     ]
+    }
+   ],
+   "source": [
+    "%%timeit\n",
+    "from medpy.metric.binary import positive_predictive_value\n",
+    "import jax.numpy as numpy\n",
+    "from jax import random\n",
+    "# 设置伪随机数种子\n",
+    "rng1=random.PRNGKey(1)\n",
+    "rng2=random.PRNGKey(2)\n",
+    "# 定义预测结果和真实标记数组\n",
+    "predict=random.randint(key=rng1,shape=(50,50),minval=0,maxval=4)\n",
+    "ground_truth=random.randint(key=rng2,shape=(50,50),minval=0,maxval=4)\n",
+    "# 计算精确度/阳性预测值\n",
+    "ppv=positive_predictive_value(predict,ground_truth)\n",
+    "print(\"精确度/阳性预测值为{}\".format(ppv))"
+   ]
   }
  ],
  "metadata": {
-- 
2.34.1


From e36dc109df784da6ee2d6071be34e2f27e4e9d6a Mon Sep 17 00:00:00 2001
From: "2563491540@qq.com" <2563491540@qq.com>
Date: Thu, 2 Feb 2023 09:31:31 +0800
Subject: [PATCH 2/2] =?UTF-8?q?created=20blogs=20folder=20and=20added=20Py?=
 =?UTF-8?q?thon=E6=A0=87=E5=87=86=E5=BA=93=E4=B9=8Bos.md=20file?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 blogs/Python标准库之os.md | 433 ++++++++++++++++++++++++++++++++++
 1 file changed, 433 insertions(+)
 create mode 100644 blogs/Python标准库之os.md

diff --git a/blogs/Python标准库之os.md b/blogs/Python标准库之os.md
new file mode 100644
index 0000000..cab2005
--- /dev/null
+++ b/blogs/Python标准库之os.md
@@ -0,0 +1,433 @@
+# 1. OS标准库简介
+
+顾名思义，OS表示Operating System，即操作系统。OS标准库是一个操作系统接口模块，提供一些方便使用操作系统相关功能的函数，具体安装位置可通过导入os模块查看`os.__file__`属性得到。当需要在Python代码中调用OS相关功能实现业务逻辑或者无法直接使用命令行工具时，我们就需要考虑导入此模块，因此有必要进行深入学习。
+
+# 2. OS标准库常用函数和属性
+
+## 2.1 文件和目录
+
+### 2.1.1 `os.getcwd()`
+
+返回表示当前工作目录的字符串
+
+```python
+print("当前工作目录为：{}".format(os.getcwd())) # 返回当前工作目录
+```
+
+![](Python标准库之os.assets/os.getcwd.JPG)
+
+### 2.1.2 `os.mkdir(path, mode=0o777, *, dir_fd=None)`
+
+以指定数字表示的权限模式mode创建一个名为path的目录。某些系统会忽略 mode，如果没有忽略，那么Linux系统来说，新建文件夹的权限=指定数字表示的权限模式mode-当前系统用户的umask默认权限，如下所示
+
+```python
+"""
+Linux操作系统可通过umask命令获得4个八进制数表示的默认权限，root用户默认是0022，普通用户默认是 0002
+第1位数代表文件所具有的特殊权限(SetUID、SetGID、Sticky BIT),后3位数表示表示umask权限值
+分别对应所有者、用户组、其他人的权限值,权限与数字对应关系为:r->4,w->2,x->1
+"""
+exit_code=os.system("umask")
+```
+
+![](Python标准库之os.assets/umask.JPG)
+
+```python
+"""
+文件夹模式mode赋值为十进制511，等价于八进制0o777
+"""
+set_mode=511
+os.mkdir(path="./cyr",mode=set_mode) # 在当前目录创建名为cyr的文件夹
+```
+
+```python
+# 长格式查看新创建的文件夹cyr可知其权限字符串为rwxr-xr-x，等价于转换后的数字权限111101101
+!ls -l | grep cyr
+```
+
+![](Python标准库之os.assets/新建文件夹cyr权限.JPG)
+
+```python
+umask_value=0o0022 # 当前系统用户八进制表示umask默认权限
+new_dir_mode=set_mode-umask_value
+print("新建文件夹的权限为:{:b}".format(new_dir_mode))
+```
+
+![](Python标准库之os.assets/新建文件夹cyr权限验证.JPG)
+
++ `os.rmdir(path, *, dir_fd=None)`
+
+  移除（删除）目录 *path*。如果目录不存在或不为空，则会分别抛出 [`FileNotFoundError`](https://docs.python.org/zh-cn/3.7/library/exceptions.html#FileNotFoundError) 或 [`OSError`](https://docs.python.org/zh-cn/3.7/library/exceptions.html#OSError) 异常。
+
+  ```python
+  os.rmdir("./cyr") # 删除空文件夹成功，无法查到cyr目录
+  !ls | grep cyr
+  ```
+
+  ```python
+  os.rmdir("./why") # 删除不存在的文件夹FileNotFoundError报错
+  ```
+
+  ![](Python标准库之os.assets/删除不存在文件夹报错.JPG)
+
+  ```python
+  os.rmdir("./nnunet/") # 删除不为空文件夹OSError报错
+  ```
+
+  ![](Python标准库之os.assets/删除不为空文件夹OSError报错.JPG)
+
++ `os.chdir(path)`
+
+  将当前工作目录更改为 path
+
+  ```python
+  print("切换前的当前工作目录为：{}".format(os.getcwd())) # 返回当前工作目录
+  dst_path="/root" # 目标文件夹
+  os.chdir(dst_path) # 将当前工作目录切换为/root
+  print("切换后的当前工作目录为：{}".format(os.getcwd())) # 返回当前工作目录
+  ```
+
+  ![](Python标准库之os.assets/os.chdir.JPG)
+
++ `os.listdir(path='.')`
+
+  返回一个包含指定path下所有文件和目录名称的按任意顺序排列的列表，特殊条目'.'和'..'除外
+
+  ```python
+  dst_path="/code/" # 目标目录
+  dirs_ls=os.listdir(path=dst_path) # 获得指定目录下全部文件和文件夹名称列表
+  print(dirs_ls)
+  ```
+
+  ![](Python标准库之os.assets/os.listdir.JPG)
+
+  
+
+## 2.2 os.path常见路径操作
+
+### 2.2.1 `os.path.abspath(path)`
+
+返回路径path 的绝对路径(标准化的)，相当于字符串拼接，路径path不存在也不会报错
+
+```python
+relative_path="tests/test_steps_for_sliding_window_prediction.py" # 路径path存在
+print("{}对应的绝对路径为{}".format(relative_path,os.path.abspath(relative_path)))
+```
+
+![](Python标准库之os.assets/os.path.abspath.JPG)
+
+```python
+no_path="tests/none.py" # 路径path不存在
+print("{}对应的绝对路径为{}".format(relative_path,os.path.abspath(no_path)))
+```
+
+![](Python标准库之os.assets/os.path.abspathno.JPG)
+
+### 2.2.2 `os.path.basename(path)`
+
+返回路径 path 的基本名称
+
+```python
+full_pathname="/proc/bus/pci/3a/08.0" # 路径path存在
+print("全路径名称对应的文件名为{}".format(os.path.basename(full_pathname)))
+```
+
+![](Python标准库之os.assets/os.path.basename.JPG)
+
+```python
+no_full_pathname="/demo/none.cpp" # 路径path不存在
+print("全路径名称对应的文件名为{}".format(os.path.basename(no_full_pathname)))
+```
+
+![image-20221126180414744](Python标准库之os.assets/image-20221126180414744.png)
+
+### 2.2.3 `os.path.dirname(path)`
+
+返回路径 path 的目录名称
+
+```python
+full_pathname="/proc/bus/pci/3a/08.0" # 路径path存在
+print("全路径名称对应的目录名称为{}".format(os.path.dirname(full_pathname)))
+```
+
+![](Python标准库之os.assets/os.path.dirname.JPG)
+
+```python
+no_full_pathname="/demo/none.cpp" # 路径path不存在
+print("全路径名称对应的目录名称为{}".format(os.path.dirname(no_full_pathname)))
+```
+
+![](Python标准库之os.assets/os.path.dirnameno.JPG)
+
+### 2.2.4 `os.path.exists(path)`
+
+判断path是否指向一个已存在路径或已打开的文件描述符，存在返回True，不存在返回False
+
+```python
+full_pathname="/proc/bus/pci/3a/08.0" # 路径path存在
+print("全路径名称对应的目录是否存在?{}".format(os.path.exists(full_pathname)))
+```
+
+![](Python标准库之os.assets/os.path.exists.JPG)
+
+```python
+no_full_pathname="/demo/none.cpp" # 路径path不存在
+print("全路径名称对应的目录是否存在?{}".format(os.path.exists(no_full_pathname)))
+```
+
+![](Python标准库之os.assets/os.path.existsno.JPG)
+
+### 2.2.5 `os.path.isabs(path)`
+
+判断path是否为一个绝对路径，是则返回True，不是或不存在则返回False。在 Unix 上，它就是以斜杠开头，而在 Windows 上，它可以是去掉驱动器号后以斜杠（或反斜杠）开头。
+
+```python
+abs_pathname="/proc/bus/pci/3a/08.0" # 路径path存在
+print("全路径名称对应的目录是否为绝对路径?{}".format(os.path.isabs(abs_pathname)))
+```
+![image-20221126193214609](Python标准库之os.assets/image-20221126193214609.png)
+```python
+rel_pathname="./nnunet/__init__.py" # 路径path是相对路径
+print("全路径名称对应的目录是否绝对路径?{}".format(os.path.isabs(rel_pathname)))
+```
+
+![image-20221126193232255](Python标准库之os.assets/image-20221126193232255.png)
+
+```python
+no_pathname="./nnunet/none.py" # 路径path是不存在
+print("全路径名称对应的目录是否绝对路径?{}".format(os.path.isabs(no_pathname)))
+```
+
+![image-20221126193244714](Python标准库之os.assets/image-20221126193244714.png)
+
+### 2.2.6 `os.path.isfile(path)`
+
+若path为指向一个已存在文件的符号链接或一个已存在文件路径，返回True。若path为一个文件夹路径或不存在路径，返回False。
+
+```shell
+ls -li /opt/conda/bin/python* # 带inode节点信息并长格式查看python开头的文件和文件夹
+```
+
+![](Python标准库之os.assets/ls_li.JPG)
+
+由上图可发现/opt/conda/bin/python为一个符号链接(软链接)指向一个已存在文件路径/opt/conda/bin/python3.7
+
+```python
+abs_pathname="/opt/conda/bin/python3.7" # path为一个已存在文件路径
+print("全路径名称对应的文件是否存在?{}".format(os.path.isfile(abs_pathname)))
+```
+
+![](Python标准库之os.assets/os.path.isfiletrue.JPG)
+
+```python
+symbolic_link="/opt/conda/bin/python" # path为指向一个已存在文件/opt/conda/bin/python3.7的符号链接
+print("全路径名称对应的文件是否存在?{}".format(os.path.isfile(symbolic_link)))
+```
+
+![](Python标准库之os.assets/os.path.isfiletrue-16695128425931.JPG)
+
+```python
+abs_path="/opt/conda/bin/" # 文件夹路径
+print("全路径名称对应的文件是否存在?{}".format(os.path.isfile(abs_path)))
+```
+
+![image-20221127093432253](Python标准库之os.assets/image-20221127093432253.png)
+
+```python
+no_full_pathname="/demo/none.cpp" # 路径path不存在
+print("全路径名称对应的文件是否存在?{}".format(os.path.isfile(no_full_pathname)))
+```
+
+![image-20221127093502677](Python标准库之os.assets/image-20221127093502677.png)
+
+### 2.2.7 `os.path.isdir(path)`
+
+若path为指向一个已存在文件夹的符号链接或一个已存在文件夹路径，返回True。若path为一个文件路径或不存在路径，返回False。
+
+```shell
+ls /code/nnunet/ # 查看已存在文件夹路径/code/nnunet/
+```
+![image-20221127110800609](Python标准库之os.assets/image-20221127110800609.png)
+
+```shell
+ln -s /code/nnunet/ ./symlink2codennunet # 当前目录即root下创建一个软链接指向一个已存在文件夹路径/code/nnunet/
+```
+
+```shell
+ls -l /root/
+```
+
+![image-20221127110142399](Python标准库之os.assets/image-20221127110142399.png)
+
+由上图可知root用户主目录下存在一个软链接symlink2codennunet指向一个已存在文件夹路径
+
+```python
+exist_dir_path="/code/nnunet/"# path为一个已存在文件夹路径
+print("全路径名称对应的文件夹是否存在?{}".format(os.path.isdir(exist_dir_path)))
+```
+
+![image-20221127111107995](Python标准库之os.assets/image-20221127111107995.png)
+
+```python
+exist_dir_symlink="/root/symlink2codennunet/"# path为指向一个已存在文件夹的符号链接
+print("全路径名称对应的文件夹是否存在?{}".format(os.path.isdir(exist_dir_symlink)))
+```
+
+![image-20221127111131025](Python标准库之os.assets/image-20221127111131025.png)
+
+```python
+exist_file_path="/opt/conda/bin/python3.7"# path为一个已存在文件路径
+print("全路径名称对应的文件夹是否存在?{}".format(os.path.isdir(exist_file_path)))
+```
+
+![image-20221127111201285](Python标准库之os.assets/image-20221127111201285.png)
+
+```python
+no_path="/demo/none.cpp" # 路径path不存在
+print("全路径名称对应的文件夹是否存在?{}".format(os.path.isdir(no_path)))
+```
+
+![image-20221127111218903](Python标准库之os.assets/image-20221127111218903.png)
+
+### 2.2.8 `os.path.islink(path)`
+
+若path代表一个已存在的符号链接，则返回True，反之则返回False。如果 Python 运行时不支持符号链接，则总是返回 False
+
+```python
+exist_symbolic_link="/opt/conda/bin/python" # path为指向一个已存在的符号链接
+print("全路径名称对应的符号链接是否存在?{}".format(os.path.islink(exist_symbolic_link)))
+```
+
+![image-20221127135410586](Python标准库之os.assets/image-20221127135410586.png)
+
+```python
+no_symbolic_link="/demo/no_link" # path为指向一个不存在的符号链接
+print("全路径名称对应的符号链接是否存在?{}".format(os.path.islink(no_symbolic_link)))
+```
+
+![image-20221127135440128](Python标准库之os.assets/image-20221127135440128.png)
+
+```python
+exist_file_path="/opt/conda/bin/python3.7"# path为一个已存在文件路径
+print("全路径名称对应的符号链接是否存在?{}".format(os.path.islink(exist_file_path)))
+```
+
+![image-20221127135526214](Python标准库之os.assets/image-20221127135526214.png)
+
+```python
+exist_dir_path="/root/"# path为一个已存在文件夹路径
+print("全路径名称对应的符号链接是否存在?{}".format(os.path.islink(exist_dir_path)))
+```
+
+![image-20221127135543707](Python标准库之os.assets/image-20221127135543707.png)
+
+### 2.2.9 `os.path.join(path, *paths)`
+
+拼接两个或多个路径部分，按需要插入`/`。如果参数中某个部分是绝对路径，则绝对路径前的路径都将被丢弃，并从绝对路径部分开始连接。如果最后一部分为空，则结果将以分隔符结尾。
+
+```python
+previous_path,abs_dirname,basename,empty_part="model","/code","demo.py",""
+```
+
+```python
+print("参数中某个部分是绝对路径拼接后为{}".format(os.path.join(previous_path,abs_dirname,basename)))
+```
+
+![image-20221127141227036](Python标准库之os.assets/image-20221127141227036.png)
+
+```python
+print("拼接两个或多个路径部分，按需要插入'/'拼接后为{}".format(os.path.join(previous_path,basename)))
+```
+
+![image-20221127141254552](Python标准库之os.assets/image-20221127141254552.png)
+
+```python
+print("最后一部分为空以分隔符结尾{}".format(os.path.join(previous_path,basename,empty_part)))
+```
+
+![image-20221127141326629](Python标准库之os.assets/image-20221127141326629.png)
+
+### 2.2.10 `os.path.normcase(path)`
+
+规范路径名称的大小写。 在 Windows 上，将路径名称中的所有字符转为小写，并将正斜杠转为反斜杠。 在其他操作系统上，将路径不加修改地返回。
+
+Linux操作系统
+
+```python
+print("当前操作系统模块名为:{}".format(os.name))
+windows_style_path=r"C:/Users\defaultuser0/APPData"
+print("Windows路径规范化后为{}".format(os.path.normcase(windows_style_path)))
+```
+
+![image-20221127142558417](Python标准库之os.assets/image-20221127142558417.png)
+
+Windows操作系统
+
+![image-20221127143000287](Python标准库之os.assets/image-20221127143000287.png)
+
+### 2.2.11 `os.path.split(path)`
+
+将路径 path 拆分为一对，即 (head, tail)，其中，tail 是路径的最后一部分，而 head 里是除最后部分外的所有内容。tail 部分不会包含斜杠，如果 path 以斜杠结尾，则 tail 将为空。如果 path 中没有斜杠，head 将为空。如果 path 为空，则 head 和 tail 均为空。head 末尾的斜杠会被去掉，除非它是根目录（即它仅包含一个或多个斜杠）。
+
+```python
+norm_path="/nnunet/configuration.py" # 一般路径
+ends_with_slash_path="/code/nnunet/" # 以斜杠结尾的路径
+no_slash_path="HIP_Logo.png" # 没有斜杠的路径
+empty_path="" # 空路径
+root_path="/" # 根目录
+print("一般路径head={},tail={}".format(*os.path.split(norm_path)))
+print("以斜杠结尾的路径head={},tail={}".format(*os.path.split(ends_with_slash_path)))
+print("没有斜杠的路径head={},tail={}".format(*os.path.split(no_slash_path)))
+print("空路径head={},tail={}".format(*os.path.split(empty_path)))
+print("根目录head={},tail={}".format(*os.path.split(root_path)))
+```
+
+![image-20221127152957405](Python标准库之os.assets/image-20221127152957405.png)
+
+### 2.2.12 `os.path.splitext(path)`
+
+将路径 path 拆分为一对，即 (root, ext)，使 root + ext == path，其中 ext 为空或以英文句点开头，且最多包含一个句点。路径前的句点将被忽略，例如 splitext('.cshrc') 返回 ('.cshrc', '')。
+
+```python
+dir_path="/code/nnunet/" # 文件夹路径
+multi_dot_file_path="/code/i.thy.py" # 包含多个句点的文件路径
+single_dot_file_path="/code/we.py" # 包含单个句点的文件路径
+starts_with_dot_file_path=".bashrc" # 以句点开头的路径
+print("文件夹路径root={},ext={}".format(*os.path.splitext(dir_path)))
+print("包含多个句点的文件路径root={},ext={}".format(*os.path.splitext(multi_dot_file_path)))
+print("包含单个句点的文件路径root={},ext={}".format(*os.path.splitext(single_dot_file_path)))
+print("以句点开头的路径root={},ext={}".format(*os.path.splitext(starts_with_dot_file_path)))
+```
+
+![image-20221127153824033](Python标准库之os.assets/image-20221127153824033.png)
+
+
+## 2.3 其他常用命令
+
+### 2.3.1 `os.name`
+
+导入的依赖特定操作系统的模块的名称，返回'posix'表示Linux，'nt'表示Windows，'java'表示Java虚拟机
+
+```python
+print("当前操作系统平台名称为{}".format(os.name))
+```
+
+![](../img/os.posix.JPG)
+
+### 2.3.2 `os.__file__`
+
+以字符串形式返回os模块安装的绝对路径
+
+```python
+     import os
+     print("os模块安装绝对路径是{}".format(os.__file__))
+```
+
+​								 ![](Python标准库之os.assets/os.__file__演示.JPG)
+
+
+# 3. 参考文献
+
++ [os --- 操作系统接口模块 — Python 3.7.13 文档](https://docs.python.org/zh-cn/3.7/library/os.html)
++ [os.path --- 常见路径操作 — Python 3.7.13 文档](https://docs.python.org/zh-cn/3.7/library/os.path.html)
++ [Linux umask详解：令新建文件和目录拥有默认权限 (biancheng.net)](http://c.biancheng.net/view/764.html)
++ [Linux chmod命令：修改文件或目录的权限 (biancheng.net)](http://c.biancheng.net/view/755.html)
-- 
2.34.1