002_Python_strftime().ipynb

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    "<small><small><i>\n",
    "All the IPython Notebooks in **Python Date Time Module** lecture series by Dr. Milaan Parmar are available @ **[GitHub](https://github.com/milaan9/08_Python_Date_Time_Module)**\n",
    "</i></small></small>"
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    "# Python `strftime()`\n",
    "\n",
    "In this class, you will learn to convert date, time and datetime objects to its equivalent string (with the help of examples).\n",
    "\n",
    "The **[strftime()](https://strftime.org/)** method returns a string representing date and time using **[date (@ Example 3), time (@ Example 7) or datetime (@ Example 9)](https://github.com/milaan9/08_Python_Date_Time_Module/blob/main/001_Python_datetime_Module.ipynb)** object."
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    "### Example 1: datetime to string using `strftime()`"
   ]
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    "The program below converts a **`datetime`** object containing current date and time to different string formats."
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      "2021-10-18 18:01:58.168321\n",
      "year: 2021\n",
      "month: 10\n",
      "day: 18\n",
      "time: 18:01:58\n",
      "date and time: 10/18/2021, 18:01:58\n",
      "date and time: 18/10/2021, 18:01:58\n"
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    "# Example 1: datetime to string using strftime()\n",
    "\n",
    "from datetime import datetime\n",
    "\n",
    "now = datetime.now() # current date and time\n",
    "print(now)\n",
    "\n",
    "year = now.strftime(\"%Y\")\n",
    "print(\"year:\", year)\n",
    "\n",
    "month = now.strftime(\"%m\")\n",
    "print(\"month:\", month)\n",
    "\n",
    "day = now.strftime(\"%d\")\n",
    "print(\"day:\", day)\n",
    "\n",
    "time = now.strftime(\"%H:%M:%S\")\n",
    "print(\"time:\", time)\n",
    "\n",
    "date_time1 = now.strftime(\"%m/%d/%Y, %H:%M:%S\")\n",
    "print(\"date and time:\",date_time1)\n",
    "\n",
    "date_time2 = now.strftime(\"%d/%m/%Y, %H:%M:%S\")\n",
    "print(\"date and time:\",date_time2)\n",
    "\n",
    "# When you run the program, the output will be something like below:"
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   "source": [
    ">**Note:** Here, **`year`**, **`day`**, **`time`** and **`date_time`** are strings, whereas **`now`** is a **`datetime`** object."
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    "## How `strftime()` works?\n",
    "\n",
    "In the above program, **`%Y`**, **`%m`**, **`%d`** etc. are format codes. The **`strftime()`** method takes one or more format codes as an argument and returns a formatted string based on it."
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   "source": [
    "1. We imported **`datetime`** class from the **`datetime`** module. It's because the object of **`datetime`** class can access **`strftime()`** method.\n",
    "\n",
    "<div>\n",
    "<img src=\"img/idt.png\" width=\"400\"/>\n",
    "</div>\n",
    "\n",
    "2. The **`datetime`** object containing current date and time is stored in **`now`** variable.\n",
    "\n",
    "<div>\n",
    "<img src=\"img/cdt.png\" width=\"400\"/>\n",
    "</div>\n",
    "\n",
    "3. The **`strftime()`** method can be used to create formatted strings.\n",
    "\n",
    "<div>\n",
    "<img src=\"img/strff1.png\" width=\"400\"/>\n",
    "</div>\n",
    "\n",
    "4. The string you pass to the **`strftime()`** method may contain more than one format codes.\n",
    "\n",
    "<div>\n",
    "<img src=\"img/strff2.png\" width=\"400\"/>\n",
    "</div>"
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   "source": [
    "### Example 2: Creating string from a timestamp"
   ]
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     "text": [
      "Date time object: 2018-06-12 15:25:22\n",
      "Output 2: 06/12/2018, 15:25:22\n",
      "Output 3: 12 Jun, 2018\n",
      "Output 4: 12 June, 2018\n",
      "Output 5: 03PM\n"
     ]
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   "source": [
    "# Example 2: Creating string from a timestamp\n",
    "\n",
    "from datetime import datetime\n",
    "\n",
    "timestamp = 1528797322\n",
    "date_time = datetime.fromtimestamp(timestamp)\n",
    "\n",
    "print(\"Date time object:\", date_time)\n",
    "\n",
    "d = date_time.strftime(\"%m/%d/%Y, %H:%M:%S\")\n",
    "print(\"Output 2:\", d)\t\n",
    "\n",
    "d = date_time.strftime(\"%d %b, %Y\")\n",
    "print(\"Output 3:\", d)\n",
    "\n",
    "d = date_time.strftime(\"%d %B, %Y\")\n",
    "print(\"Output 4:\", d)\n",
    "\n",
    "d = date_time.strftime(\"%I%p\")\n",
    "print(\"Output 5:\", d)\n",
    "\n",
    "# When you run the program, the output will be something like below:"
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    "## Format Code List\n",
    "\n",
    "The table below shows all the codes that you can pass to the **`strftime()`** method.\n",
    "\n",
    "| Directive | Meaning | Example |\n",
    "|:----: |:---- |:---- |\n",
    "| **`%a`**  | **Abbreviated weekday name.**   | **Sun, Mon, ...** |  \n",
    "| **`%A`**  | **Full weekday name.**   | **Sunday, Monday, ...** |  \n",
    "| **`%w`**  | **Weekday as a decimal number.**   | **0, 1, ..., 6** |  \n",
    "| **`%d`**  | **Day of the month as a zero-padded decimal.**   | **01, 02, ..., 31** |  \n",
    "| **`%-d`** | **Day of the month as a decimal number.**   | **1, 2, ..., 30** |  \n",
    "| **`%b`**  | **Abbreviated month name.**   | **Jan, Feb, ..., Dec** |  \n",
    "| **`%B`**  | **Full month name.**   | **January, February, ...** |  \n",
    "| **`%m`**  | **Month as a zero-padded decimal number.**   | **01, 02, ..., 12** |  \n",
    "| **`%-m`** | **Month as a decimal number.**   | **1, 2, ..., 12** |  \n",
    "| **`%y`**  | **Year without century as a zero-padded decimal number.**   | **00, 01, ..., 99** |  \n",
    "| **`%-y`** | **Year without century as a decimal number.**   | **0, 1, ..., 99** |  \n",
    "| **`%Y`**  | **Year with century as a decimal number.**   | **2013, 2019 etc.** |  \n",
    "| **`%H`**  | **Hour (24-hour clock) as a zero-padded decimal number.**   | **00, 01, ..., 23** |  \n",
    "| **`%-H`** | **Hour (24-hour clock) as a decimal number.**   | **0, 1, ..., 23** |  \n",
    "| **`%I`**  | **Hour (12-hour clock) as a zero-padded decimal number.**   | **01, 02, ..., 12** |  \n",
    "| **`%-I`** | **Hour (12-hour clock) as a decimal number.**   | **1, 2, ... 12** |  \n",
    "| **`%p`**  | **Locale’s AM or PM.**   | **AM, PM** |  \n",
    "| **`%M`**  | **Minute as a zero-padded decimal number.**   | **00, 01, ..., 59** |  \n",
    "| **`%-M`** | **Minute as a decimal number.**   | **0, 1, ..., 59** |  \n",
    "| **`%S`**  | **Second as a zero-padded decimal number.**   | **00, 01, ..., 59** |  \n",
    "| **`%-S`** | **Second as a decimal number.**   | **0, 1, ..., 59** |  \n",
    "| **`%f`**  | **Microsecond as a decimal number, zero-padded on the left.**   | **000000 - 999999** |  \n",
    "| **`%z`**  | **UTC offset in the form +HHMM or -HHMM.**   |  |  \n",
    "| **`%Z`**  | **Time zone name.**   |  |  \n",
    "| **`%j`**  | **Day of the year as a zero-padded decimal number.**   | **001, 002, ..., 366** |  \n",
    "| **`%-j`** | **Day of the year as a decimal number.**   | **1, 2, ..., 366** |  \n",
    "| **`%U`**  | **Week number of the year (Sunday as the first day of the week). All days in a new year preceding the first Sunday are considered to be in week 0.**   | **00, 01, ..., 53** |  \n",
    "| **`%U`**  | **Week number of the year (Monday as the first day of the week). All days in a new year preceding the first Monday are considered to be in week 0.**   | **00, 01, ..., 53** |  \n",
    "| **`%c`**  | **Locale’s appropriate date and time representation.**   | **Mon Sep 30 07:06:05 2013** |  \n",
    "| **`%x`**  | **Locale’s appropriate date representation.**   | **09/30/13** |  \n",
    "| **`%X`**  | **Locale’s appropriate time representation.**   | **07:06:05** |  \n",
    "| **`%%`**  | **A literal '%' character.**   | **%** | "
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   "source": [
    "### Example 3: Locale's appropriate date and time"
   ]
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      "Output 1: Tue Jun 12 15:25:22 2018\n",
      "Output 2: 06/12/18\n",
      "Output 3: 15:25:22\n"
     ]
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   "source": [
    "# Example 3: Locale's appropriate date and time\n",
    "\n",
    "from datetime import datetime\n",
    "\n",
    "timestamp = 1528797322\n",
    "date_time = datetime.fromtimestamp(timestamp)\n",
    "\n",
    "d = date_time.strftime(\"%c\")\n",
    "print(\"Output 1:\", d)\t\n",
    "\n",
    "d = date_time.strftime(\"%x\")\n",
    "print(\"Output 2:\", d)\n",
    "\n",
    "d = date_time.strftime(\"%X\")\n",
    "print(\"Output 3:\", d)\n",
    "\n",
    "# When you run the program, the output will be something like below:"
   ]
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   "source": [
    ">**Note:** Format codes **`%c`**, **`%x`** and **`%X`** are used for locale's appropriate date and time representation."
   ]
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We also recommend you to check **[Python strptime()](https://github.com/milaan9/08_Python_Date_Time_Module/blob/main/003_Python_strptime%28%29.ipynb)**. The **`strptime()`** method creates a **`datetime`** object from a string."
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