Course 4 - Python Programming for Data Science & AI/PY0101EN-4-2-WriteFile.ipynb

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   "source": [
    "<p style=\"text-align:center\">\n",
    "    <a href=\"https://skills.network/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork1005-2023-01-01\">\n",
    "    <img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/assets/logos/SN_web_lightmode.png\" width=\"200\" alt=\"Skills Network Logo\"  />\n",
    "    </a>\n",
    "</p>\n",
    "\n",
    "\n",
    "# Write and Save Files in Python\n",
    "\n",
    "\n",
    "Estimated time needed: **25** minutes\n",
    "    \n",
    "\n",
    "## Objectives\n",
    "\n",
    "After completing this lab you will be able to:\n",
    "\n",
    "* Write to files using Python libraries\n"
   ]
  },
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   "source": [
    "<h2>Table of Contents</h2>\n",
    "<div class=\"alert alert-block alert-info\" style=\"margin-top: 20px\">\n",
    "    <ul>\n",
    "        <li><a href=\"write\">Writing Files</a></li>\n",
    "        <li><a href=\"Append\">Appending Files</a></li>\n",
    "        <li><a href=\"add\">Additional File modes</a></li>\n",
    "        <li><a href=\"copy\">Copy a File</a></li>\n",
    "    </ul>\n",
    "\n",
    "</div>\n",
    "\n",
    "<hr>\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0aad7e75-a10e-4d6b-a6fa-7b8e6ae82b59",
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   "source": [
    "<h2 id=\"write\">Writing Files</h2>\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "b953e7ed-c116-47aa-b945-c6addbd9ed87",
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   "source": [
    " We can open a file object using the method <code>write()</code> to save the text file to a list. To write to a file, the mode argument must be set to **w**. Let’s write a file **Example2.txt** with the line: **“This is line A”**\n"
   ]
  },
  {
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   "source": [
    "# Write line to file\n",
    "exmp2 = 'Example2.txt'\n",
    "with open(exmp2, 'w') as writefile:\n",
    "    writefile.write(\"This is line A\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "3d8fb837-2234-4844-a14b-fc6d2ec44526",
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   "source": [
    " We can read the file to see if it worked:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "2d9a7153-a902-475c-99cd-8cfae56072d2",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "This is line A\n"
     ]
    }
   ],
   "source": [
    "# Read file\n",
    "\n",
    "with open(exmp2, 'r') as testwritefile:\n",
    "    print(testwritefile.read())"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "91ceb8c1-25a8-47c2-ab01-c47c388f39bd",
   "metadata": {},
   "source": [
    "We can write multiple lines:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "9c3c489e-c742-4b87-bd14-c372d2fa3888",
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   "source": [
    "# Write lines to file\n",
    "\n",
    "with open(exmp2, 'w') as writefile:\n",
    "    writefile.write(\"This is line A\\n\")\n",
    "    writefile.write(\"This is line B\\n\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "b633e601-9982-423d-b842-3a5c6688538c",
   "metadata": {},
   "source": [
    "The method <code>.write()</code> works similar to the method <code>.readline()</code>, except instead of reading a new line it writes a new line. The process is illustrated in the figure. The different colour coding of the grid represents a new line added to the file after each method call.\n"
   ]
  },
  {
   "cell_type": "markdown",
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   "source": [
    "<img src=\"https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%204/images/WriteLine.png\" width=\"500\">\n"
   ]
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   "metadata": {},
   "source": [
    "You can check the file to see if your results are correct \n"
   ]
  },
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   "cell_type": "code",
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   "id": "47a4058a-40d7-40f9-b57c-10bd48f864e0",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "This is line A\n",
      "This is line B\n",
      "\n"
     ]
    }
   ],
   "source": [
    "# Check whether write to file\n",
    "\n",
    "with open(exmp2, 'r') as testwritefile:\n",
    "    print(testwritefile.read())"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "06adb900-3fed-4c6c-9245-1acf68e9fca2",
   "metadata": {},
   "source": [
    " We write a list to a **.txt** file  as follows:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "d2705039-c3ac-4c8e-8d13-46528c347e44",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Sample list of text\n",
    "\n",
    "Lines = [\"This is line A\\n\", \"This is line B\\n\", \"This is line C\\n\"]\n",
    "Lines"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "fa49cedc-aebb-467d-8dc6-2107bc2cd86d",
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   "source": [
    "# Write the strings in the list to text file\n",
    "\n",
    "with open('Example2.txt', 'w') as writefile:\n",
    "    for line in Lines:\n",
    "        print(line)\n",
    "        writefile.write(line)"
   ]
  },
  {
   "cell_type": "markdown",
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   "source": [
    " We can verify the file is written by reading it and printing out the values:  \n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "676fdfc2-1d32-4bc5-b870-f55d54d5d787",
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   "source": [
    "# Verify if writing to file is successfully executed\n",
    "\n",
    "with open('Example2.txt', 'r') as testwritefile:\n",
    "    print(testwritefile.read())"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "243eed9e-e8cf-40a5-a119-b60a7fbee08b",
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   "source": [
    "However, note that setting the mode to __w__ overwrites all the existing data in the file.\n"
   ]
  },
  {
   "cell_type": "code",
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   "id": "2898a059-0e51-45c5-9144-d39c4867c2c4",
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   "source": [
    "with open('Example2.txt', 'w') as writefile:\n",
    "    writefile.write(\"Overwrite\\n\")\n",
    "with open('Example2.txt', 'r') as testwritefile:\n",
    "    print(testwritefile.read())"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "c3ca16e2-87a3-4234-843f-f0380eac803a",
   "metadata": {},
   "source": [
    "<hr>\n",
    "<h2 id=\"Append\">Appending Files</h2>\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "6947bbcb-cf23-46ac-980a-03d6aa083d92",
   "metadata": {},
   "source": [
    " We can write to files without losing any of the existing data as follows by setting the mode argument to append: **a**.  you can append a new line as follows:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "0e80fa54-e585-46de-a87a-7b88966c64d8",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write a new line to text file\n",
    "\n",
    "with open('Example2.txt', 'a') as testwritefile:\n",
    "    testwritefile.write(\"This is line C\\n\")\n",
    "    testwritefile.write(\"This is line D\\n\")\n",
    "    testwritefile.write(\"This is line E\\n\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ca3e6c93-bfc8-4b13-b821-abfccae2c717",
   "metadata": {},
   "source": [
    " You can verify the file has changed by running the following cell:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "73587698-1b49-4cdc-ac45-80be3afdce94",
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   "outputs": [],
   "source": [
    "# Verify if the new line is in the text file\n",
    "\n",
    "with open('Example2.txt', 'r') as testwritefile:\n",
    "    print(testwritefile.read())"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "556aa82f-cc92-4574-9d9c-0f4dbb87f971",
   "metadata": {},
   "source": [
    "<hr>\n",
    "<h2 id=\"add\">Additional modes</h2> \n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ab1fe386-cf2e-4196-afd6-834931a2fa16",
   "metadata": {},
   "source": [
    "It's fairly ineffecient to open the file in **a** or **w** and then reopening it in **r** to read any lines. Luckily we can access the file in the following modes:\n",
    "- **r+** : Reading and writing. Cannot truncate the file.\n",
    "- **w+** : Writing and reading. Truncates the file.\n",
    "- **a+** : Appending and Reading. Creates a new file, if none exists.\n",
    "You dont have to dwell on the specifics of each mode for this lab. \n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "e79bdffb-50d6-46bd-9a9a-849dea2c1ba9",
   "metadata": {},
   "source": [
    "Let's try out the __a+__ mode:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "96cf48ef-1282-4169-a823-891e8dadacb8",
   "metadata": {},
   "outputs": [],
   "source": [
    "with open('Example2.txt', 'a+') as testwritefile:\n",
    "    testwritefile.write(\"This is line E\\n\")\n",
    "    print(testwritefile.read())"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0c635a0e-c0bf-49cd-96c4-b22c41e4c0c5",
   "metadata": {},
   "source": [
    "There were no errors but <code>read()</code> also did not output anything. This is because of our location in the file.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "7b652b3a-5a39-4166-8197-42dd5ffd1b84",
   "metadata": {},
   "source": [
    "Most of the file methods we've looked at work in a certain location in the file. <code>.write() </code> writes at a certain location in the file. <code>.read()</code> reads at a certain location in the file and so on. You can think of this as moving your pointer around in the notepad to make changes at specific location.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "fc994253-0012-49a5-bd4d-f9071e8c6cb0",
   "metadata": {},
   "source": [
    "Opening the file in **w** is akin to opening the .txt file, moving your cursor to the beginning of the text file, writing new text and deleting everything that follows.\n",
    "Whereas opening the file in **a** is similiar to opening the .txt file, moving your cursor to the very end and then adding the new pieces of text. <br>\n",
    "It is often very useful to know where the 'cursor' is in a file and be able to control it. The following methods allow us to do precisely this -\n",
    "- <code>.tell()</code> - returns the current position in bytes\n",
    "- <code>.seek(offset,from)</code> - changes the position by 'offset' bytes with respect to 'from'. From can take the value of 0,1,2 corresponding to beginning, relative to current position and end\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "c48abda6-83e0-4491-b13c-fdf5c895b131",
   "metadata": {},
   "source": [
    "Now lets revisit **a+**\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "b32e2b3a-2b0f-4df5-a7a6-883833d20185",
   "metadata": {},
   "outputs": [],
   "source": [
    "with open('Example2.txt', 'a+') as testwritefile:\n",
    "    print(\"Initial Location: {}\".format(testwritefile.tell()))\n",
    "    \n",
    "    data = testwritefile.read()\n",
    "    if (not data):  #empty strings return false in python\n",
    "            print('Read nothing') \n",
    "    else: \n",
    "            print(testwritefile.read())\n",
    "            \n",
    "    testwritefile.seek(0,0) # move 0 bytes from beginning.\n",
    "    \n",
    "    print(\"\\nNew Location : {}\".format(testwritefile.tell()))\n",
    "    data = testwritefile.read()\n",
    "    if (not data): \n",
    "            print('Read nothing') \n",
    "    else: \n",
    "            print(data)\n",
    "    \n",
    "    print(\"Location after read: {}\".format(testwritefile.tell()) )"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "002e7bef-e62f-4f55-a13e-97bd2a212d7a",
   "metadata": {},
   "source": [
    "Finally, a note on the difference between **w+** and **r+**. Both of these modes allow access to read and write methods, however, opening a file in **w+** overwrites it and deletes all pre-existing data. <br>\n",
    "To work with a file on existing data, use **r+** and **a+**. While using **r+**, it can be useful to add a <code>.truncate()</code> method at the end of your data. This will reduce the file to your data and delete everything that follows. <br>\n",
    "In the following code block, Run the code as it is first and then run it with the <code>.truncate()</code>.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "467065d6-de10-4bc3-82a9-2c9586a8599e",
   "metadata": {},
   "outputs": [],
   "source": [
    "with open('Example2.txt', 'r+') as testwritefile:\n",
    "    data = testwritefile.readlines()\n",
    "    testwritefile.seek(0,0) #write at beginning of file\n",
    "   \n",
    "    testwritefile.write(\"Line 1\" + \"\\n\")\n",
    "    testwritefile.write(\"Line 2\" + \"\\n\")\n",
    "    testwritefile.write(\"Line 3\" + \"\\n\")\n",
    "    testwritefile.write(\"finished\\n\")\n",
    "    #Uncomment the line below\n",
    "    #testwritefile.truncate()\n",
    "    testwritefile.seek(0,0)\n",
    "    print(testwritefile.read())\n",
    "    "
   ]
  },
  {
   "cell_type": "markdown",
   "id": "86f6b0bf-ff6c-445c-b652-33b5844218d8",
   "metadata": {},
   "source": [
    "<hr>\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "b1aaf3de-882a-497d-a085-905599429c30",
   "metadata": {},
   "source": [
    "<h2 id=\"copy\">Copy a File</h2> \n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "a6a7fd46-3a3c-4fc7-acf6-e59723f2a9f5",
   "metadata": {},
   "source": [
    "Let's copy the file **Example2.txt** to the file **Example3.txt**:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "2c355396-add5-4234-a4bf-10b259f272b7",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Copy file to another\n",
    "\n",
    "with open('Example2.txt','r') as readfile:\n",
    "    with open('Example3.txt','w') as writefile:\n",
    "          for line in readfile:\n",
    "                writefile.write(line)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "3d683dea-cf4c-4d5f-993b-b8fe54e01288",
   "metadata": {},
   "source": [
    "We can read the file to see if everything works:\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "edb585a5-b1c4-41a1-ab80-694b27d3877f",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Verify if the copy is successfully executed\n",
    "\n",
    "with open('Example3.txt','r') as testwritefile:\n",
    "    print(testwritefile.read())"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "0aaa75ce-8ba4-400b-a21d-92f133cef6df",
   "metadata": {},
   "source": [
    " After reading files, we can also write data into files and save them in different file formats like **.txt, .csv, .xls (for excel files) etc**. You will come across these in further examples\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "7b3a517c-2866-42ba-bb16-050298d64a88",
   "metadata": {},
   "source": [
    "**NOTE:** If you wish to open and view the `example3.txt` file, download this lab [here](https://cf-courses-data.s3.us.cloud-object-storage.appdomain.cloud/IBMDeveloperSkillsNetwork-PY0101EN-SkillsNetwork/labs/Module%204/PY0101EN-4-2-WriteFile.ipynb) and run it locally on your machine. Then go to the working directory to ensure the `example3.txt` file exists and contains the summary data that we wrote.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "2af2e095-b644-4a20-ae9e-36f9c9c9655b",
   "metadata": {},
   "source": [
    "<hr>\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "984be040-f553-4cb8-be26-195f90e942bd",
   "metadata": {},
   "source": [
    "<h2> Exercise </h2>\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "cacdc02d-a7e2-4c0d-b805-adc39621acef",
   "metadata": {},
   "source": [
    "Your local university's Raptors fan club maintains a register of its active members on a .txt document. Every month they update the file by removing the members who are not active. You have been tasked with automating this with your Python skills. <br>\n",
    "Given the file `currentMem`, Remove each member with a 'no' in their Active column. Keep track of each of the removed members and append them to the `exMem` file. Make sure that the format of the original files in preserved.   (*Hint: Do this by reading/writing whole lines and ensuring the header remains* )\n",
    "<br>\n",
    "Run the code block below prior to starting the exercise. The skeleton code has been provided for you. Edit only the `cleanFiles` function.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "2d49902e-7b19-4c69-8483-e2736b2abba4",
   "metadata": {},
   "outputs": [],
   "source": [
    "#Run this prior to starting the exercise\n",
    "from random import randint as rnd\n",
    "\n",
    "memReg = 'members.txt'\n",
    "exReg = 'inactive.txt'\n",
    "fee =('yes','no')\n",
    "\n",
    "def genFiles(current,old):\n",
    "    with open(current,'w+') as writefile: \n",
    "        writefile.write('Membership No  Date Joined  Active  \\n')\n",
    "        data = \"{:^13}  {:<11}  {:<6}\\n\"\n",
    "\n",
    "        for rowno in range(20):\n",
    "            date = str(rnd(2015,2020))+ '-' + str(rnd(1,12))+'-'+str(rnd(1,25))\n",
    "            writefile.write(data.format(rnd(10000,99999),date,fee[rnd(0,1)]))\n",
    "\n",
    "\n",
    "    with open(old,'w+') as writefile: \n",
    "        writefile.write('Membership No  Date Joined  Active  \\n')\n",
    "        data = \"{:^13}  {:<11}  {:<6}\\n\"\n",
    "        for rowno in range(3):\n",
    "            date = str(rnd(2015,2020))+ '-' + str(rnd(1,12))+'-'+str(rnd(1,25))\n",
    "            writefile.write(data.format(rnd(10000,99999),date,fee[1]))\n",
    "\n",
    "\n",
    "genFiles(memReg,exReg)\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "9a3342e1-f7db-4af6-a80a-c5de0185a5c0",
   "metadata": {},
   "source": [
    "Now that you've run the prerequisite code cell above, which prepared the files for this exercise, you are ready to move on to the implementation.\n",
    "\n",
    "#### **Exercise:** Implement the cleanFiles function in the code cell below.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "df4d2ad3-aa2d-4007-9de1-15ef08eed1ed",
   "metadata": {},
   "outputs": [],
   "source": [
    "  \n",
    "'''\n",
    "The two arguments for this function are the files:\n",
    "    - currentMem: File containing list of current members\n",
    "    - exMem: File containing list of old members\n",
    "    \n",
    "    This function should remove all rows from currentMem containing 'no' \n",
    "    in the 'Active' column and appends them to exMem.\n",
    "    '''\n",
    "def cleanFiles(currentMem, exMem):\n",
    "    # TODO: Open the currentMem file as in r+ mode\n",
    "        #TODO: Open the exMem file in a+ mode\n",
    "\n",
    "        #TODO: Read each member in the currentMem (1 member per row) file into a list.\n",
    "        # Hint: Recall that the first line in the file is the header.\n",
    "\n",
    "        #TODO: iterate through the members and create a new list of the innactive members\n",
    "\n",
    "        # Go to the beginning of the currentMem file\n",
    "        # TODO: Iterate through the members list. \n",
    "        # If a member is inactive, add them to exMem, otherwise write them into currentMem\n",
    "\n",
    "        \n",
    "    \n",
    "    pass # Remove this line when done implementation\n",
    "\n",
    "\n",
    "# The code below is to help you view the files.\n",
    "# Do not modify this code for this exercise.\n",
    "memReg = 'members.txt'\n",
    "exReg = 'inactive.txt'\n",
    "cleanFiles(memReg,exReg)\n",
    "\n",
    "\n",
    "headers = \"Membership No  Date Joined  Active  \\n\"\n",
    "with open(memReg,'r') as readFile:\n",
    "    print(\"Active Members: \\n\\n\")\n",
    "    print(readFile.read())\n",
    "    \n",
    "with open(exReg,'r') as readFile:\n",
    "    print(\"Inactive Members: \\n\\n\")\n",
    "    print(readFile.read())\n",
    "                \n",
    "    "
   ]
  },
  {
   "cell_type": "markdown",
   "id": "28980564-e44a-4b02-a3cb-d779ac01f971",
   "metadata": {},
   "source": [
    "The code cell below is to verify your solution. Please do not modify the code and run it to test your implementation of `cleanFiles`.\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "c0e1c34c-f0a5-45f3-a089-2a8e0c581928",
   "metadata": {},
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   "source": [
    "def testMsg(passed):\n",
    "    if passed:\n",
    "       return 'Test Passed'\n",
    "    else :\n",
    "       return 'Test Failed'\n",
    "\n",
    "testWrite = \"testWrite.txt\"\n",
    "testAppend = \"testAppend.txt\" \n",
    "passed = True\n",
    "\n",
    "genFiles(testWrite,testAppend)\n",
    "\n",
    "with open(testWrite,'r') as file:\n",
    "    ogWrite = file.readlines()\n",
    "\n",
    "with open(testAppend,'r') as file:\n",
    "    ogAppend = file.readlines()\n",
    "\n",
    "try:\n",
    "    cleanFiles(testWrite,testAppend)\n",
    "except:\n",
    "    print('Error')\n",
    "\n",
    "with open(testWrite,'r') as file:\n",
    "    clWrite = file.readlines()\n",
    "\n",
    "with open(testAppend,'r') as file:\n",
    "    clAppend = file.readlines()\n",
    "        \n",
    "# checking if total no of rows is same, including headers\n",
    "\n",
    "if (len(ogWrite) + len(ogAppend) != len(clWrite) + len(clAppend)):\n",
    "    print(\"The number of rows do not add up. Make sure your final files have the same header and format.\")\n",
    "    passed = False\n",
    "    \n",
    "for line in clWrite:\n",
    "    if  'no' in line:\n",
    "        passed = False\n",
    "        print(\"Inactive members in file\")\n",
    "        break\n",
    "    else:\n",
    "        if line not in ogWrite:\n",
    "            print(\"Data in file does not match original file\")\n",
    "            passed = False\n",
    "print (\"{}\".format(testMsg(passed)))\n",
    "    \n",
    "\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ed07c1d3-52af-48b4-b9aa-f0057083d484",
   "metadata": {},
   "source": [
    "<details><summary>Click here for the solution</summary>\n",
    "\n",
    "```python\n",
    "def cleanFiles(currentMem,exMem):\n",
    "    with open(currentMem,'r+') as writeFile: \n",
    "        with open(exMem,'a+') as appendFile:\n",
    "            #get the data\n",
    "            writeFile.seek(0)\n",
    "            members = writeFile.readlines()\n",
    "            #remove header\n",
    "            header = members[0]\n",
    "            members.pop(0)\n",
    "                \n",
    "            inactive = [member for member in members if ('no' in member)]\n",
    "            '''\n",
    "            The above is the same as \n",
    "\n",
    "            for member in members:\n",
    "            if 'no' in member:\n",
    "                inactive.append(member)\n",
    "            '''\n",
    "            #go to the beginning of the write file\n",
    "            writeFile.seek(0) \n",
    "            writeFile.write(header)\n",
    "            for member in members:\n",
    "                if (member in inactive):\n",
    "                    appendFile.write(member)\n",
    "                else:\n",
    "                    writeFile.write(member)      \n",
    "            writeFile.truncate()\n",
    "                \n",
    "memReg = 'members.txt'\n",
    "exReg = 'inactive.txt'\n",
    "cleanFiles(memReg,exReg)\n",
    "\n",
    "# code to help you see the files\n",
    "\n",
    "headers = \"Membership No  Date Joined  Active  \\n\"\n",
    "\n",
    "with open(memReg,'r') as readFile:\n",
    "    print(\"Active Members: \\n\\n\")\n",
    "    print(readFile.read())\n",
    "    \n",
    "with open(exReg,'r') as readFile:\n",
    "    print(\"Inactive Members: \\n\\n\")\n",
    "    print(readFile.read())\n",
    "    \n",
    "```\n",
    "\n",
    "</details>\n",
    "\n",
    "    \n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "b995a411-9b0b-4200-963a-e7aba5647dc3",
   "metadata": {},
   "source": [
    "<hr>\n",
    "<h2>The last exercise!</h2>\n",
    "<p>Congratulations, you have completed this lesson and hands-on lab in Python. \n",
    "<hr>\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "d37fdea6-f5b4-4af5-87a9-a1f8a06c0951",
   "metadata": {},
   "source": [
    "## Author\n",
    "\n",
    "<a href=\"https://www.linkedin.com/in/joseph-s-50398b136/?utm_medium=Exinfluencer&utm_source=Exinfluencer&utm_content=000026UJ&utm_term=10006555&utm_id=NA-SkillsNetwork-Channel-SkillsNetworkCoursesIBMDeveloperSkillsNetworkPY0101ENSkillsNetwork1005-2023-01-01\">Joseph Santarcangelo</a>\n",
    "\n",
    "\n",
    "### Other Contributors\n",
    "<a href=\"www.linkedin.com/in/jiahui-mavis-zhou-a4537814a\">Mavis Zhou</a>\n",
    "\n",
    "\n",
    "## Change Log\n",
    "\n",
    "\n",
    "|  Date (YYYY-MM-DD) |  Version | Changed By  |  Change Description |\n",
    "|---|---|---|---|\n",
    "| 2022-01-10  | 2.1  | Malika  | Removed the readme for GitShare|\n",
    "| 2020-10-16  | 1.3  | Arjun Swani  |  Added exercise |\n",
    "| 2020-10-16  | 1.2  | Arjun Swani  |  Added section additional file modes |\n",
    "| 2020-10-16  | 1.1  | Arjun Swani |  Made append a different section |\n",
    "| 2020-08-28  | 0.2  | Lavanya  |  Moved lab to course repo in GitLab |\n",
    "\n",
    "\n",
    "\n",
    "<hr>\n",
    "\n",
    "## <h3 align=\"center\"> © IBM Corporation 2020. All rights reserved. <h3/>\n"
   ]
  }
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