datetime_lokalizace.ipynb

{
  "nbformat": 4,
  "nbformat_minor": 0,
  "metadata": {
    "colab": {
      "name": "datetime lokalizace.ipynb",
      "provenance": []
    },
    "kernelspec": {
      "name": "python3",
      "display_name": "Python 3"
    }
  },
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "-SJkVAjpWTGR",
        "colab_type": "text"
      },
      "source": [
        "V Pyhonu většinou pracujeme s datetime v UTC, ale navíc bez nastavené timezone - tzv. naive"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "1WIhHvViWPHP",
        "colab_type": "code",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 85
        },
        "outputId": "f7043165-e19d-44ed-ea83-6f1ed77efb01"
      },
      "source": [
        "from datetime import datetime\n",
        "\n",
        "dt_naive = datetime.utcnow()\n",
        "print(dt_naive)\n",
        "print(dt_naive.isoformat())\n",
        "print(dt_naive.tzinfo)\n",
        "print(dt_naive.tzname())"
      ],
      "execution_count": 19,
      "outputs": [
        {
          "output_type": "stream",
          "text": [
            "2019-11-22 13:48:10.817739\n",
            "2019-11-22T13:48:10.817739\n",
            "None\n",
            "None\n"
          ],
          "name": "stdout"
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "2F46WWf0Ws8K",
        "colab_type": "text"
      },
      "source": [
        "Pomocí knihovny [pytz](https://pypi.org/project/pytz/) si to převedeme do datetime se správně nastaveným tzinfo na UTC (protože ten naive datetime byl v UTC)"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "CGCvDZrgWkIS",
        "colab_type": "code",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 85
        },
        "outputId": "f8b17288-08ae-44f2-9550-c714ed5341f4"
      },
      "source": [
        "import pytz\n",
        "\n",
        "dt_utc = pytz.utc.localize(dt_naive)\n",
        "print(dt_utc)\n",
        "print(dt_utc.isoformat())\n",
        "print(dt_utc.tzinfo)\n",
        "print(dt_utc.tzname())"
      ],
      "execution_count": 20,
      "outputs": [
        {
          "output_type": "stream",
          "text": [
            "2019-11-22 13:48:10.817739+00:00\n",
            "2019-11-22T13:48:10.817739+00:00\n",
            "UTC\n",
            "UTC\n"
          ],
          "name": "stdout"
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "5dFAb-QxXAvh",
        "colab_type": "text"
      },
      "source": [
        "A teď už to můžeme opět pomocí pytz převést do libovolné timezone"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "N81AUo9-W3Le",
        "colab_type": "code",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 85
        },
        "outputId": "5ec461ea-f753-4b18-e54e-260f3eee0629"
      },
      "source": [
        "dt_prg = pytz.timezone('Europe/Prague').normalize(dt_utc)\n",
        "print(dt_prg)\n",
        "print(dt_prg.isoformat())\n",
        "print(dt_prg.tzinfo)\n",
        "print(dt_prg.tzname())"
      ],
      "execution_count": 21,
      "outputs": [
        {
          "output_type": "stream",
          "text": [
            "2019-11-22 14:48:10.817739+01:00\n",
            "2019-11-22T14:48:10.817739+01:00\n",
            "Europe/Prague\n",
            "CET\n"
          ],
          "name": "stdout"
        }
      ]
    }
  ]
}