23_디렉토리와_파일_관리.ipynb

{"nbformat":4,"nbformat_minor":0,"metadata":{"colab":{"name":"23_디렉토리와_파일_관리.ipynb","provenance":[],"collapsed_sections":[]},"language_info":{"codemirror_mode":{"name":"ipython","version":3},"file_extension":".py","mimetype":"text/x-python","name":"python","nbconvert_exporter":"python","pygments_lexer":"ipython3","version":"3.6.5"},"kernelspec":{"name":"python3","display_name":"Python 3"},"accelerator":"GPU"},"cells":[{"cell_type":"markdown","metadata":{"id":"yqIHrQCTJ-_h"},"source":["# 운영체제(Operating System) 이용\n","\n","운영체제도 프로그램이므로 실행에 필요한 변수를 정의하고 사용한다.\n","응용 프로그램은 운영체제 내에서 실행되기 때문에 운영체제는 응용 프로그램의 환경으로 볼 수 있다.\n","이런 의미로 운영체제에서 정의한 변수를 환경변수라고 한다.\n","응용 프로그램은 환경변수를 비롯한 운영체제에 대한 정보 뿐만 아니라 운영체제가 제공하는 기능도 이용해야 한다.\n","이를 지원하기 위한 라이브러리가 `os`이다."]},{"cell_type":"code","metadata":{"id":"ANlYZnvJJ-_j"},"source":["import os"],"execution_count":null,"outputs":[]},{"cell_type":"markdown","metadata":{"id":"4Gfw9uiLJ-_p"},"source":["환경변수에 대한 정보는 `environ` 객체를 통해 얻을 수 있다.\n","이 객체는 `dict` 객체와 유사한 방법으로 이용할 수 있다.\n","즉 `[]` 연산자를 이용해서 환경변수를 조회하거나 추가할 수 있다.\n","\n","Note: `set` 명령으로 명령창에서 환경변수를 조회할 수 있다.\n","특정 환경변수의 값을 조회할 때는 `echo %환경변수%` 명령을 내리면 된다."]},{"cell_type":"code","metadata":{"scrolled":true,"id":"XeKKKjNwJ-_r","colab":{"base_uri":"https://localhost:8080/","height":54},"outputId":"24ab6795-c0dc-4c00-b55f-258ba828990e"},"source":["print(os.environ)"],"execution_count":null,"outputs":[{"output_type":"stream","text":["environ({'ENV': '/root/.bashrc', 'GCS_READ_CACHE_BLOCK_SIZE_MB': '16', 'CLOUDSDK_CONFIG': '/content/.config', 'CUDA_VERSION': '10.0.130', 'PATH': '/usr/local/bin:/usr/local/nvidia/bin:/usr/local/cuda/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/tools/node/bin:/tools/google-cloud-sdk/bin:/opt/bin', 'HOME': '/root', 'LD_LIBRARY_PATH': '/usr/local/nvidia/lib:/usr/local/nvidia/lib64', 'LANG': 'en_US.UTF-8', 'SHELL': '/bin/bash', 'LIBRARY_PATH': '/usr/local/cuda/lib64/stubs', 'CUDA_PKG_VERSION': '10-0=10.0.130-1', 'SHLVL': '1', 'NCCL_VERSION': '2.4.2', 'NVIDIA_VISIBLE_DEVICES': 'all', 'TF_FORCE_GPU_ALLOW_GROWTH': 'true', 'DEBIAN_FRONTEND': 'noninteractive', 'CUDNN_VERSION': '7.5.1.10', 'LAST_FORCED_REBUILD': '20190507', 'JPY_PARENT_PID': '24', 'PYTHONPATH': '/env/python', 'DATALAB_SETTINGS_OVERRIDES': '{\"kernelManagerProxyPort\":6000,\"kernelManagerProxyHost\":\"172.28.0.3\",\"jupyterArgs\":[\"--ip=\\\\\"172.28.0.2\\\\\"\"]}', 'NO_GCE_CHECK': 'True', 'GLIBCXX_FORCE_NEW': '1', 'NVIDIA_DRIVER_CAPABILITIES': 'compute,utility', '_': '/tools/node/bin/node', 'LD_PRELOAD': '/usr/lib/x86_64-linux-gnu/libtcmalloc.so.4', 'NVIDIA_REQUIRE_CUDA': 'cuda>=10.0 brand=tesla,driver>=384,driver<385 brand=tesla,driver>=410,driver<411', 'OLDPWD': '/', 'HOSTNAME': '1f966208400b', 'COLAB_GPU': '0', 'PWD': '/', 'GLIBCPP_FORCE_NEW': '1', 'PYTHONWARNINGS': 'ignore:::pip._internal.cli.base_command', 'TERM': 'xterm-color', 'CLICOLOR': '1', 'PAGER': 'cat', 'GIT_PAGER': 'cat', 'MPLBACKEND': 'module://ipykernel.pylab.backend_inline'})\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"hICnzJCYJ-_z","colab":{"base_uri":"https://localhost:8080/","height":112},"outputId":"20143f1d-9d35-4858-a1bf-ee6e75424744"},"source":["print(os.environ['HOME'])\n","# print(os.environ['HOMEPATH'])\n","print(os.environ['PATH'])\n","print(os.environ['LD_LIBRARY_PATH'])\n","print(os.environ['HOSTNAME'])"],"execution_count":null,"outputs":[{"output_type":"stream","text":["/root\n","/usr/local/bin:/usr/local/nvidia/bin:/usr/local/cuda/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/tools/node/bin:/tools/google-cloud-sdk/bin:/opt/bin\n","/usr/local/nvidia/lib:/usr/local/nvidia/lib64\n","eb9a885aac0c\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"kBQQatFgp8Wx"},"source":["## 운영체제에 관한 정보 알아보기\n","\n","예를 들어 Colab이 실행되는 운영체제에 관한 정보는 다음과 같이 확인 할 수 있다. \n","Jupyter Notebook에서 운영체제의 명령을 내릴 때는 ! 을 쓴 다음에 명령을 내리면 된다."]},{"cell_type":"code","metadata":{"id":"LixfKrFkqD2V","colab":{"base_uri":"https://localhost:8080/","height":34},"outputId":"5cf413c3-0f33-465e-d464-08dab1fd2da3"},"source":["# 파이썬의 버전 알아보기\n","!python --version"],"execution_count":null,"outputs":[{"output_type":"stream","text":["Python 3.6.7\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"zvSWQwLyqHcx","colab":{"base_uri":"https://localhost:8080/","height":34},"outputId":"5fbdf66b-977e-42cf-cbbb-b19bf1cf2505"},"source":["# Colab이 실행되는 가상 컴퓨터의 운영체제가 무엇인지 확인 할 수 있다. \n","!cat /etc/issue.net"],"execution_count":null,"outputs":[{"output_type":"stream","text":["Ubuntu 18.04.2 LTS\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"p-SpzlTkqM9d","colab":{"base_uri":"https://localhost:8080/","height":194},"outputId":"0e1e0017-e647-4f9f-8c05-248590978b69"},"source":["# Colab이 실행되는 가상 컴퓨터의 CPU 사양을 알아볼 수 있다.\n","!head /proc/cpuinfo"],"execution_count":null,"outputs":[{"output_type":"stream","text":["processor\t: 0\n","vendor_id\t: GenuineIntel\n","cpu family\t: 6\n","model\t\t: 63\n","model name\t: Intel(R) Xeon(R) CPU @ 2.30GHz\n","stepping\t: 0\n","microcode\t: 0x1\n","cpu MHz\t\t: 2300.000\n","cache size\t: 46080 KB\n","physical id\t: 0\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"t4t08h4sqwlC","colab":{"base_uri":"https://localhost:8080/","height":70},"outputId":"5a56d285-00f5-402b-8bca-86ba99ff1e2e"},"source":["# Colab이 실행되는 가상 컴퓨터의 메모리에 관한 정보를 알아볼 수 있다.\n","!head -n 3 /proc/meminfo"],"execution_count":null,"outputs":[{"output_type":"stream","text":["MemTotal:       13335268 kB\n","MemFree:        11583908 kB\n","MemAvailable:   12687372 kB\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"5PUlcPf3rUyI","colab":{"base_uri":"https://localhost:8080/","height":158},"outputId":"b51b3223-d848-4f89-d01f-9eb6eb3e8608"},"source":["# Colab이 실행되는 가상 컴퓨터의 파일시스템에 대해 알아볼 수 있다.\n","!df -h"],"execution_count":null,"outputs":[{"output_type":"stream","text":["Filesystem      Size  Used Avail Use% Mounted on\n","overlay          49G   23G   24G  49% /\n","tmpfs           6.4G     0  6.4G   0% /dev\n","tmpfs           6.4G     0  6.4G   0% /sys/fs/cgroup\n","tmpfs           6.4G  8.0K  6.4G   1% /var/colab\n","/dev/sda1        55G   24G   32G  44% /etc/hosts\n","shm             6.0G     0  6.0G   0% /dev/shm\n","tmpfs           6.4G     0  6.4G   0% /sys/firmware\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"4YFPe2_trsmr","colab":{"base_uri":"https://localhost:8080/","height":318},"outputId":"d796d2da-89ee-47e7-f8de-b1e959bb38a1"},"source":["# Jupyter Notebook의 런타임 탭에서 런타임 유형 변경을 클릭 후 하드웨어 가속기를 GPU로 변경하면\n","# GPU에 관한 정보를 확인할 수 있다.\n","\n","!nvidia-smi"],"execution_count":null,"outputs":[{"output_type":"stream","text":["Mon May 27 14:27:03 2019       \n","+-----------------------------------------------------------------------------+\n","| NVIDIA-SMI 418.67       Driver Version: 410.79       CUDA Version: 10.0     |\n","|-------------------------------+----------------------+----------------------+\n","| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |\n","| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |\n","|===============================+======================+======================|\n","|   0  Tesla T4            Off  | 00000000:00:04.0 Off |                    0 |\n","| N/A   42C    P8    15W /  70W |      0MiB / 15079MiB |      0%      Default |\n","+-------------------------------+----------------------+----------------------+\n","                                                                               \n","+-----------------------------------------------------------------------------+\n","| Processes:                                                       GPU Memory |\n","|  GPU       PID   Type   Process name                             Usage      |\n","|=============================================================================|\n","|  No running processes found                                                 |\n","+-----------------------------------------------------------------------------+\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"4Wv7JBYQJ-_3"},"source":["## `import` 문장에서 기재된 모듈을 검색할 경로\n","\n","파이썬 프로그램에서 모듈 또는 패키지를 `import할 때 모듈 이름만 기재한다.\n","즉 모듈이 어떤 디렉토리에 있는지는 기재하지 않는다.\n","왜냐하면 모듈이나 패키지를 검색할 경로가 이미 지정되어 있기 때문이다.\n","`import` 문장에 기재된 모듈을 검색할 경로는 `sys` 모듈의 `path`에 저장되어 있다.\n","`sys.path`는 리스트이며 프로그램 내에서 새로운 경로를 추가할 수도 있다."]},{"cell_type":"code","metadata":{"id":"V-uU_tdTpQPi","colab":{"base_uri":"https://localhost:8080/","height":54},"outputId":"e4bc2e49-4190-4122-d9cc-f5c42411d714"},"source":["import sys\n","print(sys.path)"],"execution_count":null,"outputs":[{"output_type":"stream","text":["['', '/env/python', '/usr/lib/python36.zip', '/usr/lib/python3.6', '/usr/lib/python3.6/lib-dynload', '/usr/local/lib/python3.6/dist-packages', '/usr/lib/python3/dist-packages', '/usr/local/lib/python3.6/dist-packages/IPython/extensions', '/root/.ipython']\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"h7dfBwioJ-_8"},"source":["## 디렉토리 관리"]},{"cell_type":"markdown","metadata":{"id":"iINgRWWyJ-_9"},"source":["### 디렉토리 구분 문자\n","\n","디렉토리는 계층구조를 가지므로 한 디렉토리를 나타내는 문자열에는 상위 디렉토리와 하위 디렉토리를 구분하기 위해 정해진 문자를 사용한다.\n","이를 디렉토리 구분 문자(delimiter, separator)라고 하면 운영체제에 따라 구분 문자가 다르다.\n","리눅스 계열의 운영체제에서는 `/`를 구분 문자로 사용하고, 윈도우 계열의 운영체제에서는 `\\`를 구분 문자로 사용한다.\n","운영체제의 디렉토리 구분 문자는 `os.sep`에 저장되어 있다.\n","프로그램을 작성할 때는 디렉토리 구분 문자를 직접 입력하지 않고 `os.sep`를 이용하는 것이 좋다. "]},{"cell_type":"code","metadata":{"id":"7RHCUnOyJ-__","colab":{"base_uri":"https://localhost:8080/","height":35},"executionInfo":{"status":"ok","timestamp":1620867809663,"user_tz":-540,"elapsed":1338,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"538f8462-5584-406c-a3e8-a46d1f50b2b1"},"source":["import os\n","os.sep"],"execution_count":2,"outputs":[{"output_type":"execute_result","data":{"application/vnd.google.colaboratory.intrinsic+json":{"type":"string"},"text/plain":["'/'"]},"metadata":{"tags":[]},"execution_count":2}]},{"cell_type":"markdown","metadata":{"id":"h4k2LuNzJ_AX"},"source":["경로는 문자열이므로 문자열의 메소드를 이용하여 경로를 조작할 수 있다.\n","특히 `split()`, `join()` 메소드는 매우 유용하다."]},{"cell_type":"code","metadata":{"id":"Gh3szOLXJ_AE","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620867845494,"user_tz":-540,"elapsed":1042,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"a464c8e0-a01d-4eb6-8e19-fcab2c3c37cc"},"source":["path = \"C:\" + os.sep + \"Users\" + os.sep + \"joong\"\n","print(path)"],"execution_count":3,"outputs":[{"output_type":"stream","text":["C:/Users/joong\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"3Uw6xFU6J_AI","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620867852849,"user_tz":-540,"elapsed":556,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"273d460d-682a-4806-beb1-423ed1d7b163"},"source":["import os\n","path = os.path.join(\"C:\", \"Users\", \"joong\")\n","print(path)"],"execution_count":4,"outputs":[{"output_type":"stream","text":["C:/Users/joong\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"DR0fwiqOJ_AP","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620867860610,"user_tz":-540,"elapsed":815,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"6f547fb5-1baf-4782-8ce9-2da594c00012"},"source":["path = os.sep.join([\"C:\", \"Users\", \"joong\"])\n","print(path)"],"execution_count":5,"outputs":[{"output_type":"stream","text":["C:/Users/joong\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"ZkvuQhuNJ_Ac"},"source":["## 여러 구분 문자\n","\n","운영체제에 따라 달라질 수 있는 구분 문자에는 디렉토리 구분 문자 외에도 줄 바꿈 문자, 파일 이름과 파일 확장자 사이에 사용하는 구분문자가 있다.\n","이 구분 문자는 `os.extsep`와 `os.linesep`에 저장되어 있다."]},{"cell_type":"code","metadata":{"id":"M3ysufH_J_Ac","colab":{"base_uri":"https://localhost:8080/","height":71},"executionInfo":{"status":"ok","timestamp":1620868351780,"user_tz":-540,"elapsed":566,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"28d52a92-4a20-48c1-c6e0-92abbd9fee98"},"source":["print(os.extsep)\n","print(os.extsep)\n","os.linesep"],"execution_count":10,"outputs":[{"output_type":"stream","text":[".\n",".\n"],"name":"stdout"},{"output_type":"execute_result","data":{"application/vnd.google.colaboratory.intrinsic+json":{"type":"string"},"text/plain":["'\\n'"]},"metadata":{"tags":[]},"execution_count":10}]},{"cell_type":"code","metadata":{"id":"uorgP6SUJ_AY","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620868665108,"user_tz":-540,"elapsed":566,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"f849e341-cd0b-4293-8e8e-bdad6ea97b6c"},"source":["path = os.getcwd()\n","print(path)\n","\n","splitted_path = path.split(os.sep)\n","print(splitted_path)\n","\n","joined_path = os.sep.join(splitted_path)\n","print(joined_path)"],"execution_count":15,"outputs":[{"output_type":"stream","text":["/content <class 'str'>\n","['', 'content']\n","/content\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"Z4Vfmw6LJ_Ag"},"source":["현재 디렉토리와 상위 디렉토리를 간단히 지정하기 위한 문자열이 있는데 이들은 `os.curdir`와 `os.pardir`에 저장되어 있다."]},{"cell_type":"code","metadata":{"id":"jQMXE9_lJ_Ah","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620868428388,"user_tz":-540,"elapsed":530,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"c7c8e85a-c3e5-4d21-e098-0cec4ca00712"},"source":["print(os.curdir)\n","print(os.pardir)"],"execution_count":11,"outputs":[{"output_type":"stream","text":[".\n","..\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"7c3N8J7mJ41J","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620868495999,"user_tz":-540,"elapsed":537,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"b4542a51-c759-4d21-f55d-05a0a9c0e471"},"source":["!ls ."],"execution_count":12,"outputs":[{"output_type":"stream","text":["sample_data\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"nY97crUzJ8X9","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620868498855,"user_tz":-540,"elapsed":790,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"12c87662-2074-4a3d-9d07-23d75ac749bf"},"source":["!ls .."],"execution_count":13,"outputs":[{"output_type":"stream","text":["bin\t datalab  home\t lib64\topt   run   sys\t\t       tools\n","boot\t dev\t  lib\t media\tproc  sbin  tensorflow-1.15.2  usr\n","content  etc\t  lib32  mnt\troot  srv   tmp\t\t       var\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"rQRXvF3uJ_Am"},"source":["## 파일과 디렉토리 관리"]},{"cell_type":"markdown","metadata":{"id":"nTSRIHtgJ_Ao"},"source":["### 현재 디렉토리와 이렉토리 이동"]},{"cell_type":"markdown","metadata":{"id":"fdmo-vP0uxkS"},"source":["현재 위치한 디렉토리는 `os.getcwd()`를 이용하면 알 수 있다. \n","현재 디렉토리를 다른 디렉토리로 이동하려면 `os.chdir(이동할디렉토리)`를 이용하면 된다."]},{"cell_type":"code","metadata":{"id":"OqF2V6m6vM_E","colab":{"base_uri":"https://localhost:8080/","height":35},"executionInfo":{"status":"ok","timestamp":1620868643404,"user_tz":-540,"elapsed":535,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"491f377e-b422-4837-cc6d-af4257501938"},"source":["os.getcwd()"],"execution_count":14,"outputs":[{"output_type":"execute_result","data":{"application/vnd.google.colaboratory.intrinsic+json":{"type":"string"},"text/plain":["'/content'"]},"metadata":{"tags":[]},"execution_count":14}]},{"cell_type":"code","metadata":{"id":"rHIG6qWuJ_A0","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620868973497,"user_tz":-540,"elapsed":748,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"4f2b6cb9-d49c-46d3-9fa1-78fb11c05f36"},"source":["cwd = os.getcwd()\n","print(cwd)\n","\n","os.chdir(os.environ['HOME'])\n","print(os.getcwd())\n","\n","os.chdir(cwd)\n","print(os.getcwd())"],"execution_count":18,"outputs":[{"output_type":"stream","text":["/content\n","/root\n","/content\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"KGPj0flKJ_BL"},"source":["### 파일과 디렉토리 목록 조회\n","\n","지정한 디렉토리 내에 위치한 파일이나 디렉토리의 이름은 `os.listdir()` 함수를 이용하면 알 수 있다."]},{"cell_type":"code","metadata":{"id":"7y8fBV9tJ_BM","colab":{"base_uri":"https://localhost:8080/","height":34},"outputId":"64ac7f1d-ce2f-4515-d8a1-2b4cc05e9a5e"},"source":["os.listdir('/content')"],"execution_count":null,"outputs":[{"output_type":"execute_result","data":{"text/plain":["['.config', 'gdrive', 'sample_data']"]},"metadata":{"tags":[]},"execution_count":49}]},{"cell_type":"code","metadata":{"id":"N6RNhz4IVKVD"},"source":["from google.colab import drive\n","drive.mount('/content/drive')"],"execution_count":null,"outputs":[]},{"cell_type":"code","metadata":{"id":"PQGe3b1TJ_BS","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620869294622,"user_tz":-540,"elapsed":519,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"ccb309fa-1577-4a9e-e580-f70d883cf060"},"source":["os.listdir('/content' + os.sep + 'sample_data')"],"execution_count":19,"outputs":[{"output_type":"execute_result","data":{"text/plain":["['anscombe.json',\n"," 'README.md',\n"," 'california_housing_train.csv',\n"," 'california_housing_test.csv',\n"," 'mnist_train_small.csv',\n"," 'mnist_test.csv']"]},"metadata":{"tags":[]},"execution_count":19}]},{"cell_type":"code","metadata":{"id":"F35EmTLqJ_BW","colab":{"base_uri":"https://localhost:8080/"},"executionInfo":{"status":"ok","timestamp":1620869317914,"user_tz":-540,"elapsed":592,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"10663eb8-dbe8-47de-c29d-2418fb7d514f"},"source":["for ele in os.listdir():\n","    print(ele, end=', ')"],"execution_count":20,"outputs":[{"output_type":"stream","text":[".config, sample_data, "],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"XpHAhOqsJ_BZ"},"source":["### 디렉토리 생성과 삭제\n","\n","함수\t| 설명\n","--- | ---\n","os.makedirs 또는 os.mkdir(디렉토리) | 디렉토리를 생성한다.\n","os.removedirs 또는 os.rmdir(디렉토리) | 디렉토리를 삭제한다.단, 디렉터리가 비어있어야 삭제가 가능하다.\n","os.rename(old_file_name, new_file_name)\t| old_file_name을 new_file_name이라는 이름으로 바꾼다."]},{"cell_type":"code","metadata":{"id":"40vU1bDXJ_Ba","colab":{"base_uri":"https://localhost:8080/","height":34},"outputId":"e09d7ed3-14de-4cf5-f6db-39506f2e6b1b"},"source":["newdir = os.getcwd() + os.sep + \"newdir\"\n","os.mkdir(newdir)\n","if 'newdir' in os.listdir():\n","    print('succeeded to create a directory')\n","else:\n","    print(\"failed to create a directory\")"],"execution_count":null,"outputs":[{"output_type":"stream","text":["succeeded to create a directory\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"J9LpyxcLM9iJ","colab":{"base_uri":"https://localhost:8080/","height":247},"outputId":"9f8b1d6d-3dac-40df-e737-8107b5e1a522"},"source":["os.listdir()"],"execution_count":null,"outputs":[{"output_type":"execute_result","data":{"text/plain":["['.profile',\n"," '.bashrc',\n"," '.local',\n"," 'newdir',\n"," '.config',\n"," '.keras',\n"," '.bash_history',\n"," '.ipython',\n"," '.cache',\n"," '.node-gyp',\n"," '.npm',\n"," '.jupyter',\n"," '.gsutil']"]},"metadata":{"tags":[]},"execution_count":53}]},{"cell_type":"code","metadata":{"id":"bhwwkN2eJ_Be","colab":{"base_uri":"https://localhost:8080/","height":34},"outputId":"61adf727-0b42-494a-f711-50e5d8e34de9"},"source":["os.removedirs(newdir)\n","if 'newdir' in os.listdir():\n","    print('failed to remove a directory')\n","else:\n","    print(\"succeeded to remove a directory\")"],"execution_count":null,"outputs":[{"output_type":"stream","text":["succeeded to remove a directory\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"naVR4D0JNEhy","colab":{"base_uri":"https://localhost:8080/","height":230},"outputId":"a7d669b1-e610-4d8b-e6e2-1680ea4dda00"},"source":["os.listdir()"],"execution_count":null,"outputs":[{"output_type":"execute_result","data":{"text/plain":["['.profile',\n"," '.bashrc',\n"," '.local',\n"," '.config',\n"," '.keras',\n"," '.bash_history',\n"," '.ipython',\n"," '.cache',\n"," '.node-gyp',\n"," '.npm',\n"," '.jupyter',\n"," '.gsutil']"]},"metadata":{"tags":[]},"execution_count":55}]},{"cell_type":"markdown","metadata":{"id":"dKW3MRgWJ_Bi"},"source":["현재 디렉토리 하위에 디렉토리를 만들거나 하위 디렉토리로 이동할 때는 디렉토리 이름만 인자로 주면 된다."]},{"cell_type":"code","metadata":{"id":"znWalWXXJ_Bl","colab":{"base_uri":"https://localhost:8080/","height":52},"outputId":"2c7c5ce2-e9e8-4586-c3a5-77b133dd9559"},"source":["if not os.path.exists('backup'):\n","    os.mkdir('backup')\n","print(os.getcwd())\n","os.listdir('backup')"],"execution_count":null,"outputs":[{"output_type":"stream","text":["/root\n"],"name":"stdout"},{"output_type":"execute_result","data":{"text/plain":["[]"]},"metadata":{"tags":[]},"execution_count":56}]},{"cell_type":"code","metadata":{"id":"i7ZKWWzhJ_Bu","colab":{"base_uri":"https://localhost:8080/","height":54},"outputId":"79d3a5bf-9d33-46aa-95c3-be3a061fe9e9"},"source":["print(', '.join(os.listdir()))"],"execution_count":null,"outputs":[{"output_type":"stream","text":[".bashrc, .profile, .ipython, backup, .local, .keras, .npm, .node-gyp, .config, .cache, .jupyter, .gsutil\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"O4kEGAtEJ_Bz"},"source":["파일을 복사하거나 이동할 때는 `shutil` 모듈에 정의된 `copy()`, `move()` 함수를 이용한다.\n","다음은 현재 디렉토리에 있는 파일 중에서 확장자가 `ipynb`, `jpg`,`'png`인 모든 파일을 하위 디렉토리 `backup`에 복사하는 프로그램이다."]},{"cell_type":"code","metadata":{"id":"1qOuMXRwJ_B0"},"source":["import shutil as sh\n","dst = 'backup'\n","exts = ('ipynb', 'jpg', 'png') # 반드시 튜플로 지정해야 한다.\n","for file in os.listdir():\n","    if file.endswith(exts):\n","        sh.copy(file, dst)"],"execution_count":null,"outputs":[]},{"cell_type":"code","metadata":{"id":"m4lvmGwTJ_B4","colab":{"base_uri":"https://localhost:8080/","height":34},"outputId":"cce4949b-ff5f-4b7d-a380-f9619482982d"},"source":["', '.join(os.listdir(dst))"],"execution_count":null,"outputs":[{"output_type":"execute_result","data":{"text/plain":["''"]},"metadata":{"tags":[]},"execution_count":51}]},{"cell_type":"markdown","metadata":{"id":"_6q6tIN9J_B9"},"source":["## 경로 처리"]},{"cell_type":"markdown","metadata":{"id":"ddvxolo4J_B9"},"source":["경로와 관련한 작업에는 다음과 같은 것들이 있다.\n","\n","1. 경로의 존재 여부 검사\n","2. 파일에 대한 경로에서 파일 이름과 그 외 부분의 분리\n","3. 상대경로를 절대경로로 변환\n","4. 디렉토리 이름을 연결하여 경로 만들기\n","\n","`os.path` 모듈에 이를 위한 함수 `exists()`, `basename()`, `dirname()`, `split()`, `join()`이 정의되어 있다."]},{"cell_type":"code","metadata":{"id":"ymAt6BB2J_CB","colab":{"base_uri":"https://localhost:8080/","height":123},"outputId":"5cf66892-b85d-43cf-a0f1-bafbe03e86ed"},"source":["import os.path\n","path ='/content/sample_data'\n","os.chdir(path)\n","print(os.getcwd())\n","print(os.path.exists(path))\n","\n","file = os.sep.join([path, \"mnist_test.csv\"])\n","print(os.path.basename(file))\n","print(os.path.dirname(file))\n","split_path = os.path.split(file)\n","print(split_path)\n","os.sep.join(split_path)"],"execution_count":null,"outputs":[{"output_type":"stream","text":["/content/sample_data\n","True\n","mnist_test.csv\n","/content/sample_data\n","('/content/sample_data', 'mnist_test.csv')\n"],"name":"stdout"},{"output_type":"execute_result","data":{"text/plain":["'/content/sample_data/mnist_test.csv'"]},"metadata":{"tags":[]},"execution_count":58}]},{"cell_type":"code","metadata":{"id":"tOThnMVH0tpE","colab":{"base_uri":"https://localhost:8080/","height":34},"outputId":"0242f33f-5b42-4bfd-d803-13e5094c56d8"},"source":["os.getcwd()"],"execution_count":null,"outputs":[{"output_type":"execute_result","data":{"text/plain":["'/content/sample_data'"]},"metadata":{"tags":[]},"execution_count":60}]},{"cell_type":"code","metadata":{"id":"7Ph8ZkMd0YSl"},"source":["import pandas as pd\n","\n","sample_data = pd.read_csv('california_housing_test.csv')"],"execution_count":null,"outputs":[]},{"cell_type":"code","metadata":{"id":"yeP3LG_H01lA","colab":{"base_uri":"https://localhost:8080/","height":217},"outputId":"f2f272c4-179b-44f6-ffb8-1409e8a830a2"},"source":["sample_data.head()"],"execution_count":null,"outputs":[{"output_type":"execute_result","data":{"text/html":["<div>\n","<style scoped>\n","    .dataframe tbody tr th:only-of-type {\n","        vertical-align: middle;\n","    }\n","\n","    .dataframe tbody tr th {\n","        vertical-align: top;\n","    }\n","\n","    .dataframe thead th {\n","        text-align: right;\n","    }\n","</style>\n","<table border=\"1\" class=\"dataframe\">\n","  <thead>\n","    <tr style=\"text-align: right;\">\n","      <th></th>\n","      <th>longitude</th>\n","      <th>latitude</th>\n","      <th>housing_median_age</th>\n","      <th>total_rooms</th>\n","      <th>total_bedrooms</th>\n","      <th>population</th>\n","      <th>households</th>\n","      <th>median_income</th>\n","      <th>median_house_value</th>\n","    </tr>\n","  </thead>\n","  <tbody>\n","    <tr>\n","      <th>0</th>\n","      <td>-122.05</td>\n","      <td>37.37</td>\n","      <td>27.0</td>\n","      <td>3885.0</td>\n","      <td>661.0</td>\n","      <td>1537.0</td>\n","      <td>606.0</td>\n","      <td>6.6085</td>\n","      <td>344700.0</td>\n","    </tr>\n","    <tr>\n","      <th>1</th>\n","      <td>-118.30</td>\n","      <td>34.26</td>\n","      <td>43.0</td>\n","      <td>1510.0</td>\n","      <td>310.0</td>\n","      <td>809.0</td>\n","      <td>277.0</td>\n","      <td>3.5990</td>\n","      <td>176500.0</td>\n","    </tr>\n","    <tr>\n","      <th>2</th>\n","      <td>-117.81</td>\n","      <td>33.78</td>\n","      <td>27.0</td>\n","      <td>3589.0</td>\n","      <td>507.0</td>\n","      <td>1484.0</td>\n","      <td>495.0</td>\n","      <td>5.7934</td>\n","      <td>270500.0</td>\n","    </tr>\n","    <tr>\n","      <th>3</th>\n","      <td>-118.36</td>\n","      <td>33.82</td>\n","      <td>28.0</td>\n","      <td>67.0</td>\n","      <td>15.0</td>\n","      <td>49.0</td>\n","      <td>11.0</td>\n","      <td>6.1359</td>\n","      <td>330000.0</td>\n","    </tr>\n","    <tr>\n","      <th>4</th>\n","      <td>-119.67</td>\n","      <td>36.33</td>\n","      <td>19.0</td>\n","      <td>1241.0</td>\n","      <td>244.0</td>\n","      <td>850.0</td>\n","      <td>237.0</td>\n","      <td>2.9375</td>\n","      <td>81700.0</td>\n","    </tr>\n","  </tbody>\n","</table>\n","</div>"],"text/plain":["   longitude  latitude  ...  median_income  median_house_value\n","0    -122.05     37.37  ...         6.6085            344700.0\n","1    -118.30     34.26  ...         3.5990            176500.0\n","2    -117.81     33.78  ...         5.7934            270500.0\n","3    -118.36     33.82  ...         6.1359            330000.0\n","4    -119.67     36.33  ...         2.9375             81700.0\n","\n","[5 rows x 9 columns]"]},"metadata":{"tags":[]},"execution_count":70}]},{"cell_type":"markdown","metadata":{"id":"dCQvcFSZVpyu"},"source":["## `pathlib` library\n","\n","디렉토리나 파일에 대한 경로를 객체지향적인 방법으로 처리하려면 `pathlib` 모듈을 이용하는 것이 좋다.\n","`pathlib.Path` 클래스의 객체를 생성하고 메소들를 이용하여 대부분의 작업을 할 수 있다."]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"BfhvjuBpVzt1","executionInfo":{"status":"ok","timestamp":1620869623635,"user_tz":-540,"elapsed":563,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"dc336ee3-5e46-40e2-f472-d2688e0f9d16"},"source":["import pathlib\n","import os\n","\n","# 현재 디렉토리에 대한 Path 객체를 생성한다.\n","path = pathlib.Path(os.getcwd())\n","print(path, type(path))"],"execution_count":33,"outputs":[{"output_type":"stream","text":["/content <class 'pathlib.PosixPath'>\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"YWUA1Cw6WWLX","executionInfo":{"status":"ok","timestamp":1620869406819,"user_tz":-540,"elapsed":718,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"002b37a2-a5c3-49f5-d854-d5fe5af96c33"},"source":["print(path.is_dir())"],"execution_count":22,"outputs":[{"output_type":"stream","text":["True\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"BsjIIxE7Wcd7","executionInfo":{"status":"ok","timestamp":1620869406820,"user_tz":-540,"elapsed":713,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"3ad1cd12-4582-43aa-d3f0-10b462e45b5f"},"source":["print(path.is_file())"],"execution_count":23,"outputs":[{"output_type":"stream","text":["False\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"Wp5jWCG2WDzu","executionInfo":{"status":"ok","timestamp":1620869406822,"user_tz":-540,"elapsed":709,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"f84961e0-17ed-462b-d507-ddab82ea406c"},"source":["for fn in path.iterdir():\n","    print(fn)"],"execution_count":24,"outputs":[{"output_type":"stream","text":["/content/.config\n","/content/sample_data\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"urxRGVapbO3s","executionInfo":{"status":"ok","timestamp":1620869406825,"user_tz":-540,"elapsed":704,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"f2542548-0de6-408e-eaf7-7f300e3d5b35"},"source":["print(path.absolute())\n","print(path.parent)\n","print(path.root)"],"execution_count":25,"outputs":[{"output_type":"stream","text":["/content\n","/\n","/\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"ogOFpm-0b1Wv","executionInfo":{"status":"ok","timestamp":1620869406825,"user_tz":-540,"elapsed":698,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"28b46e1b-ff31-42a1-d84a-aeae17364de3"},"source":["subdir = path / \"temp\"\n","print(type(subdir), subdir)"],"execution_count":26,"outputs":[{"output_type":"stream","text":["<class 'pathlib.PosixPath'> /content/temp\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"ag1fkP5hentJ","executionInfo":{"status":"ok","timestamp":1620869407067,"user_tz":-540,"elapsed":934,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"7d9022f6-f8c7-4318-f97f-03f5268164e7"},"source":["print(subdir.exists())"],"execution_count":27,"outputs":[{"output_type":"stream","text":["False\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"UrAqSr4Kb6zt","executionInfo":{"status":"ok","timestamp":1620869407069,"user_tz":-540,"elapsed":934,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}}},"source":["subdir.mkdir()"],"execution_count":28,"outputs":[]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"ckVJDz0Wd-fr","executionInfo":{"status":"ok","timestamp":1620869407070,"user_tz":-540,"elapsed":928,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"8e7d2a8c-0157-4504-b110-a0f7e7b62112"},"source":["print(subdir.is_dir())"],"execution_count":29,"outputs":[{"output_type":"stream","text":["True\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"0S9xLk3Vd1F3","executionInfo":{"status":"ok","timestamp":1620869407071,"user_tz":-540,"elapsed":922,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"59d0e279-9c48-47af-e3ad-f1070cff4ebc"},"source":["for fn in path.iterdir():\n","    print(fn)"],"execution_count":30,"outputs":[{"output_type":"stream","text":["/content/.config\n","/content/temp\n","/content/sample_data\n"],"name":"stdout"}]},{"cell_type":"code","metadata":{"id":"GINSJXOxeDn2","executionInfo":{"status":"ok","timestamp":1620869407072,"user_tz":-540,"elapsed":919,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}}},"source":["subdir.rmdir()"],"execution_count":31,"outputs":[]},{"cell_type":"code","metadata":{"colab":{"base_uri":"https://localhost:8080/"},"id":"9cr2sc67eIRZ","executionInfo":{"status":"ok","timestamp":1620869407074,"user_tz":-540,"elapsed":914,"user":{"displayName":"JoongYang Park","photoUrl":"https://lh3.googleusercontent.com/a-/AOh14Gil_iGJWBEYzWtFHlz-1-blMGzZwleJmxAMeTZVDg=s64","userId":"06333572283827112098"}},"outputId":"31a7d658-47c7-41b5-aecf-9aff28d171b4"},"source":["for fn in path.iterdir():\n","    print(fn)"],"execution_count":32,"outputs":[{"output_type":"stream","text":["/content/.config\n","/content/sample_data\n"],"name":"stdout"}]},{"cell_type":"markdown","metadata":{"id":"M1xDl6u6J_CE"},"source":["## 연습문제\n","\n","1. 현재 디렉토리를 알아보시오.\n","2. 환경변수와 그 값을 알아보시오.\n","3. 새로운 환경변수를 추가해보시오.\n","4. 현재 디렉토리 상위에 library라는 이름의 새로운 디렉토리를 생성하시오.\n","5. 현재 디렉토리에 있는 jupyter notebook을 library 디렉토리에 복사하시오,\n","6. 현재 운영체제에서 사용하는 디렉토리 구분문자를 알아보시오.\n","7. 연동된 구글 드라이브에 dataset 디렉토리를  생성하시오."]}]}