diff --git a/notebooks/seminar05.ipynb b/notebooks/seminar05.ipynb
index 66b888bf9e609ba157477aa8af01e2b5f5139e4a..f2a0a07d8b1fac62047d6a75caf8be900cf2b765 100644
--- a/notebooks/seminar05.ipynb
+++ b/notebooks/seminar05.ipynb
@@ -20,9 +20,7 @@
     "(Buch: http://greenteapress.com/thinkpython2/html/thinkpython2006.html)\n",
     "## Exkurs: Was mir an Python gefällt\n",
     "\n",
-    "In dieser Rubrik, die immer am Anfang eines Kapitels steht, möchte ich Ihnen zeigen, wofür ich Python nutze und warum ich es mag. Sie werden vielleicht noch nicht verstehen, was ich genau mache, aber Sie sehen damit schon einmal die Möglichkeiten von Python und können später darauf zurückgreifen. Da dies auch ein Exkurs ist, können Sie diese Rubrik gerne auch erst einmal überspringen.\n",
-    "\n",
-    "Mit den Operatoren aus diesem Kapitel können wir ganz leicht das Verfahren zur Umwandlung einer Dezimalzahl in ihre Binärdarstellung implementieren:"
+    "Wir wünschen Ihnen ein frohes Fest und einen guten Rutsch ins neue Jahr."
    ]
   },
   {
@@ -31,37 +29,73 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# Umwandlung einer positiven, ganzen Dezimalzahl in Binärdarstellung (als Zeichenkette)\n",
-    "def dez_zu_bin(n):\n",
-    "    ergebnis = \"\"\n",
-    "    while n > 0:\n",
-    "        ergebnis = str(n % 2) + ergebnis\n",
-    "        n = n // 2\n",
-    "    return ergebnis\n",
-    "\n",
-    "print(dez_zu_bin(42))\n",
-    "\n",
-    "# Und weil wir heute beim Thema Rekursion sind ...\n",
-    "def dez_zu_bin_rekursiv(n):\n",
-    "    if n == 0:\n",
-    "        return \"\"\n",
-    "    return dez_zu_bin_rekursiv(n // 2) + str(n % 2)\n",
-    "\n",
-    "print(dez_zu_bin_rekursiv(42))\n",
-    "\n",
-    "# Warum eigentlich auf ein Zahlensystem festlegen?\n",
-    "def dez_zu_allem(n, s):\n",
-    "    if n == 0:\n",
-    "        return \"\"\n",
-    "    return dez_zu_allem(n // len(s), s) + s[n % len(s)]\n",
-    "\n",
-    "print(dez_zu_allem(42, \"01\"))\n",
-    "print(dez_zu_allem(42, \"0123456789\"))\n",
-    "print(dez_zu_allem(42, \"01234567\"))\n",
-    "print(dez_zu_allem(42, \"0123456789ABCDEF\"))\n",
-    "print(dez_zu_allem(42, \"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ\"))"
+    "\"\"\" \n",
+    "Quelle: https://teampython.wordpress.com/2015/12/12/print-a-christmas-tree/\n",
+    "Python 3 version by antiloquax (2015), based on code from datamungeblog.com.\n",
+    "\"\"\"\n",
+    " \n",
+    "from random import choice\n",
+    "from random import random\n",
+    " \n",
+    "# If you change this, use an odd number.\n",
+    "size = 21\n",
+    "\n",
+    "# Probability that a character will be green.\n",
+    "prob_gr = 0.6\n",
+    "# Colour codes.\n",
+    "colours = [31, 33, 34, 35, 36, 37]\n",
+    "# Characters to use for decorations. Experiment with these.\n",
+    "# The chr(169) and chr(174) characters may not work in all terminals\n",
+    "# (extended ASCII, c and r in a circle).\n",
+    "decs = ['@', '&', '*', chr(169), chr(174)]\n",
+    "\n",
+    "# Format string for printing blinking characters.\n",
+    "blink_col = \"\\033[5;{0}m{1}\\033[0m\"\n",
+    "# String to print a green octothorpe ('#').\n",
+    "leaf = \"\\033[32m#\\033[0m\"\n",
+    "\n",
+    "# Width of the tree, will grow by 2 each time.\n",
+    "width = 1\n",
+    "# Initialise the tree string, with a star at the top.\n",
+    "tree = \"\\n{}*\\n\".format(' ' * (size))\n",
+    "\n",
+    "\"\"\" Main Loop starts now.\"\"\"\n",
+    " \n",
+    "\"\"\" We can't use the normal \"format\" centering approach:\n",
+    "    (\"{:^nn}\".format(string) where \"nn\" is the width of the line), \n",
+    "    with these ansi codes. This is because Python sees the strings as being\n",
+    "    more than one character long (15 & 10 for baubles and leaves).\"\"\"\n",
+    "\n",
+    "# Loop from (size - 1) down to 0, using the counter as the padding size.\n",
+    "for pad in range(size - 1, -1, -1):\n",
+    "    # Increase the width of the tree by 2.\n",
+    "    width += 2\n",
+    "     \n",
+    "    # Put the characters for the line in \"temp\".\n",
+    "    temp = \"\"\n",
+    "    for j in range(width):\n",
+    "        # Make some leaves.\n",
+    "        if random() < prob_gr:\n",
+    "            temp += leaf\n",
+    "        # And also some baubles.\n",
+    "        else:\n",
+    "            temp += blink_col.format(choice(colours), choice(decs))\n",
+    "\n",
+    "    # Add that string to the line, with padding.\n",
+    "    tree += \"{0}{1}\\n\".format(' ' * pad, temp)\n",
+    "\n",
+    "# Add a \"trunk\" of 2 lines and return.\n",
+    "print(tree + \"{0}{1}\\n\".format(' ' * (size - 1), \"000\") * 2)\n",
+    "print(\"\\x46\\x72\\x6f\\x68\\x65\\x20\\x46\\x65\\x73\\x74\\x74\\x61\\x67\\x65\\x21\")"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
diff --git a/notebooks/seminar07.ipynb b/notebooks/seminar07.ipynb
index 550bd18c56ed06900d84e9afb402a910c2d1a2ed..13fde6b61429b5714dfe1302b0c9c50fb28fb15c 100644
--- a/notebooks/seminar07.ipynb
+++ b/notebooks/seminar07.ipynb
@@ -29,7 +29,9 @@
    "source": [
     "## Exkurs: Was mir an Python gefällt\n",
     "\n",
-    "Wir wünschen Ihnen ein frohes Fest und einen guten Rutsch ins neue Jahr."
+    "In dieser Rubrik, die immer am Anfang eines Kapitels steht, möchte ich Ihnen zeigen, wofür ich Python nutze und warum ich es mag. Sie werden vielleicht noch nicht verstehen, was ich genau mache, aber Sie sehen damit schon einmal die Möglichkeiten von Python und können später darauf zurückgreifen. Da dies auch ein Exkurs ist, können Sie diese Rubrik gerne auch erst einmal überspringen.\n",
+    "\n",
+    "Mit den Operatoren aus diesem Kapitel können wir ganz leicht das Verfahren zur Umwandlung einer Dezimalzahl in ihre Binärdarstellung implementieren:"
    ]
   },
   {
@@ -38,64 +40,35 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "\"\"\" \n",
-    "Quelle: https://teampython.wordpress.com/2015/12/12/print-a-christmas-tree/\n",
-    "Python 3 version by antiloquax (2015), based on code from datamungeblog.com.\n",
-    "\"\"\"\n",
-    " \n",
-    "from random import choice\n",
-    "from random import random\n",
-    " \n",
-    "# If you change this, use an odd number.\n",
-    "size = 21\n",
-    "\n",
-    "# Probability that a character will be green.\n",
-    "prob_gr = 0.6\n",
-    "# Colour codes.\n",
-    "colours = [31, 33, 34, 35, 36, 37]\n",
-    "# Characters to use for decorations. Experiment with these.\n",
-    "# The chr(169) and chr(174) characters may not work in all terminals\n",
-    "# (extended ASCII, c and r in a circle).\n",
-    "decs = ['@', '&', '*', chr(169), chr(174)]\n",
-    "\n",
-    "# Format string for printing blinking characters.\n",
-    "blink_col = \"\\033[5;{0}m{1}\\033[0m\"\n",
-    "# String to print a green octothorpe ('#').\n",
-    "leaf = \"\\033[32m#\\033[0m\"\n",
-    "\n",
-    "# Width of the tree, will grow by 2 each time.\n",
-    "width = 1\n",
-    "# Initialise the tree string, with a star at the top.\n",
-    "tree = \"\\n{}*\\n\".format(' ' * (size))\n",
-    "\n",
-    "\"\"\" Main Loop starts now.\"\"\"\n",
-    " \n",
-    "\"\"\" We can't use the normal \"format\" centering approach:\n",
-    "    (\"{:^nn}\".format(string) where \"nn\" is the width of the line), \n",
-    "    with these ansi codes. This is because Python sees the strings as being\n",
-    "    more than one character long (15 & 10 for baubles and leaves).\"\"\"\n",
-    "\n",
-    "# Loop from (size - 1) down to 0, using the counter as the padding size.\n",
-    "for pad in range(size - 1, -1, -1):\n",
-    "    # Increase the width of the tree by 2.\n",
-    "    width += 2\n",
-    "     \n",
-    "    # Put the characters for the line in \"temp\".\n",
-    "    temp = \"\"\n",
-    "    for j in range(width):\n",
-    "        # Make some leaves.\n",
-    "        if random() < prob_gr:\n",
-    "            temp += leaf\n",
-    "        # And also some baubles.\n",
-    "        else:\n",
-    "            temp += blink_col.format(choice(colours), choice(decs))\n",
-    "\n",
-    "    # Add that string to the line, with padding.\n",
-    "    tree += \"{0}{1}\\n\".format(' ' * pad, temp)\n",
-    "\n",
-    "# Add a \"trunk\" of 2 lines and return.\n",
-    "print(tree + \"{0}{1}\\n\".format(' ' * (size - 1), \"000\") * 2)\n",
-    "print(\"\\x46\\x72\\x6f\\x68\\x65\\x20\\x46\\x65\\x73\\x74\\x74\\x61\\x67\\x65\\x21\")"
+    "# Umwandlung einer positiven, ganzen Dezimalzahl in Binärdarstellung (als Zeichenkette)\n",
+    "def dez_zu_bin(n):\n",
+    "    ergebnis = \"\"\n",
+    "    while n > 0:\n",
+    "        ergebnis = str(n % 2) + ergebnis\n",
+    "        n = n // 2\n",
+    "    return ergebnis\n",
+    "\n",
+    "print(dez_zu_bin(42))\n",
+    "\n",
+    "# Und weil wir heute beim Thema Rekursion sind ...\n",
+    "def dez_zu_bin_rekursiv(n):\n",
+    "    if n == 0:\n",
+    "        return \"\"\n",
+    "    return dez_zu_bin_rekursiv(n // 2) + str(n % 2)\n",
+    "\n",
+    "print(dez_zu_bin_rekursiv(42))\n",
+    "\n",
+    "# Warum eigentlich auf ein Zahlensystem festlegen?\n",
+    "def dez_zu_allem(n, s):\n",
+    "    if n == 0:\n",
+    "        return \"\"\n",
+    "    return dez_zu_allem(n // len(s), s) + s[n % len(s)]\n",
+    "\n",
+    "print(dez_zu_allem(42, \"01\"))\n",
+    "print(dez_zu_allem(42, \"0123456789\"))\n",
+    "print(dez_zu_allem(42, \"01234567\"))\n",
+    "print(dez_zu_allem(42, \"0123456789ABCDEF\"))\n",
+    "print(dez_zu_allem(42, \"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ\"))"
    ]
   },
   {