ch05-Python标准库/05-02模块os：与操作系统进行交互.ipynb

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  {
   "cell_type": "markdown",
   "id": "367b1906",
   "metadata": {},
   "source": [
    "# 模块os：与操作系统进行交互"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "6e43f203",
   "metadata": {},
   "outputs": [],
   "source": [
    "import os"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "5e41003c",
   "metadata": {},
   "source": [
    "## 文件相关操作"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "dc63fb5c",
   "metadata": {},
   "source": [
    "当前工作目录："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "659e2eaa",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'/Users/lijin/Documents/Projects/notes-python3/ch05-Python标准库'"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.getcwd()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ad09ea7f",
   "metadata": {},
   "source": [
    "当前工作目录符号："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "d1efc1ce",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'.'"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.curdir"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "973b6abd",
   "metadata": {},
   "source": [
    "当前目录下得的文件："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "45839732",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "['05-01模块sys：系统相关.ipynb', '05-02模块os：与操作系统进行交互.ipynb', '.ipynb_checkpoints']"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.listdir(os.curdir)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ac75c1c5",
   "metadata": {},
   "source": [
    "生成一个新文件："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "d8490e61",
   "metadata": {},
   "outputs": [],
   "source": [
    "with open(\"test.file\", \"w\") as f:\n",
    "    pass"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "0b669f68",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "\"test.file\" in os.listdir(os.curdir)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "a65854c3",
   "metadata": {},
   "source": [
    "重命名文件："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "0f68dfcd",
   "metadata": {},
   "outputs": [],
   "source": [
    "os.rename(\"test.file\", \"test.file.new\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "029a32c1",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "False"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "\"test.file\" in os.listdir(os.curdir)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "82c25fa8",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "\"test.file.new\" in os.listdir(os.curdir)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0ed254bb",
   "metadata": {},
   "source": [
    "删除文件："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "id": "ba2c81c6",
   "metadata": {},
   "outputs": [],
   "source": [
    "os.remove(\"test.file.new\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "8f19dafe",
   "metadata": {},
   "source": [
    "## 系统常量"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "8f34c7c4",
   "metadata": {},
   "source": [
    "当前操作系统的换行符："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "id": "1a9f327d",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'\\n'"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.linesep"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "59b11639",
   "metadata": {},
   "source": [
    "当前操作系统的路径分隔符："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "id": "8f6ca52b",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'/'"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.sep"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "c43a76e8",
   "metadata": {},
   "source": [
    "当前操作系统的环境变量PATH中的分隔符："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "id": "a71790d1",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "':'"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.pathsep"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "6558a0b8",
   "metadata": {},
   "source": [
    "环境变量："
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "id": "512d3481",
   "metadata": {},
   "outputs": [
    {
     "data": {
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       "environ{'TERM_SESSION_ID': 'w0t1p0:7462DF5B-09C1-4821-83FD-C724311C2A67',\n",
       "        'SSH_AUTH_SOCK': '/private/tmp/com.apple.launchd.uX0G3b36Nf/Listeners',\n",
       "        'LC_TERMINAL_VERSION': '3.4.12',\n",
       "        'COLORFGBG': '7;0',\n",
       "        'ITERM_PROFILE': 'Default',\n",
       "        'XPC_FLAGS': '0x0',\n",
       "        'LANG': 'zh_CN.UTF-8',\n",
       "        'PWD': '/Users/lijin/Documents/Projects/notes-python3',\n",
       "        'SHELL': '/bin/zsh',\n",
       "        '__CFBundleIdentifier': 'com.googlecode.iterm2',\n",
       "        'SECURITYSESSIONID': '186a3',\n",
       "        'TERM_PROGRAM_VERSION': '3.4.12',\n",
       "        'TERM_PROGRAM': 'iTerm.app',\n",
       "        'PATH': '/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin',\n",
       "        'LC_TERMINAL': 'iTerm2',\n",
       "        'COLORTERM': 'truecolor',\n",
       "        'COMMAND_MODE': 'unix2003',\n",
       "        'TERM': 'xterm-color',\n",
       "        'HOME': '/Users/lijin',\n",
       "        'TMPDIR': '/var/folders/jy/yvmv88r909s2y0qzjw2ryn7m0000gn/T/',\n",
       "        'USER': 'lijin',\n",
       "        'XPC_SERVICE_NAME': '0',\n",
       "        'LOGNAME': 'lijin',\n",
       "        'LaunchInstanceID': 'C2B95C62-AE3E-47FF-BD5E-0EF65304B9FE',\n",
       "        '__CF_USER_TEXT_ENCODING': '0x1F5:0x19:0x34',\n",
       "        'ITERM_SESSION_ID': 'w0t1p0:7462DF5B-09C1-4821-83FD-C724311C2A67',\n",
       "        'SHLVL': '1',\n",
       "        'OLDPWD': '/Users/lijin',\n",
       "        'ZSH': '/Users/lijin/.oh-my-zsh',\n",
       "        'PAGER': 'cat',\n",
       "        'LESS': '-R',\n",
       "        'LSCOLORS': 'Gxfxcxdxbxegedabagacad',\n",
       "        '_': '/usr/local/bin/jupyter',\n",
       "        'PYDEVD_USE_FRAME_EVAL': 'NO',\n",
       "        'JPY_PARENT_PID': '861',\n",
       "        'CLICOLOR': '1',\n",
       "        'GIT_PAGER': 'cat',\n",
       "        'MPLBACKEND': 'module://matplotlib_inline.backend_inline'}"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "os.environ"
   ]
  },
  {
   "attachments": {},
   "cell_type": "markdown",
   "id": "f6396792",
   "metadata": {},
   "source": [
    "## os.path模块\n",
    "\n",
    "在不同的操作系统下进行操作时，不同的路径规范可能会带来一定的麻烦。Python提供了os.path子模块解决这个问题。\n",
    "\n",
    "os.path是os模块下的一个子模块，它有很多与路径相关的功能，比如对文件路径属性的判断：\n",
    "- `os.path.isfile(path)`：检测路径是否为文件。\n",
    "- `os.path.isdir(path)`：检测路径是否为文件夹。\n",
    "- `os.path.exists(path)`：检测路径是否存在。\n",
    "- `os.path.isabs(path)`：检测路径是否为绝对路径。\n",
    "\n",
    "os.path模块最主要的功能还是路径分隔符相关的操作。\n",
    "Window的路径分隔符是“\\”，而Linux/Mac的路径分隔符是“/”，需要合成或者分开路径时，不同的操作系统下所产生的路径不同，可以用os.path模块统一解决这个问题：\n",
    "\n",
    "- `os.path.join(a, *p)`：使用系统分隔符，将各个部分合并为一个路径。\n",
    "- `os.path.join(a, *p)`：使用系统分隔符，将各个部分合并为一个路径。\n",
    "\n",
    "例如，os.path.join(\"test\", \"a.txt\")在Windows系统下会变成：\n",
    "```\n",
    "test\\a.txt\n",
    "```\n",
    "在Linux/Mac系统下会变成\n",
    "```\n",
    "test/a.txt\n",
    "```"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "bf82325c",
   "metadata": {},
   "outputs": [],
   "source": []
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