diff --git a/labs02/task03.py b/labs02/task03.py
index a1c3a85..3524bb2 100644
--- a/labs02/task03.py
+++ b/labs02/task03.py
@@ -13,7 +13,13 @@ jak 'set', która przechowuje elementy bez powtórzeń.)
 
 
 def oov(text, vocab):
-    pass
+    def test(self):
+        """Prosty test."""
+        text = "This is a string , which I will use for string testing"
+        vocab = [',', 'this', 'is', 'a', 'which', 'for', 'will', 'I']
+        oo_voc = ['string', 'testing', 'use']
+
+        self.assertEqual(set(oov(text, vocab)), set(oo_voc))
 
 
 
diff --git a/labs02/task05.py b/labs02/task05.py
index f59268a..51eba86 100644
--- a/labs02/task05.py
+++ b/labs02/task05.py
@@ -10,7 +10,21 @@ np. odległość pomiędzy punktami (0, 0, 0) i (3, 4, 0) jest równa 5.
 """
 
 def euclidean_distance(x, y):
-    pass
+    def test_special_cases(self):
+        """Testy przypadków szczególnych."""
+        self.assertAlmostEqual(
+            euclidean_distance((0.0, 0.0, 0.0), (0.0, 0.0, 0.0)), 0.0)
+        self.assertAlmostEqual(
+            euclidean_distance((3.6, -1.7, 0.3), (3.6, -1.7, 0.3)), 0.0)
+        self.assertAlmostEqual(
+            euclidean_distance((2.3, 4.3, -7.5), (2.3, 8.5, -7.5)), 4.2)
+
+    def test_regular_cases(self):
+        """Testy dla zwykłych przypadków"""
+        self.assertAlmostEqual(
+            euclidean_distance((0.0, 0.0, 0.0), (0.0, 4.0, 3.0)), 5.0)
+        self.assertAlmostEqual(
+            euclidean_distance((2.4, -5.1, 3.0), (5.3, 2.1, 10.0)), 10.4523, 3)
 
 def tests(f):
     inputs = [[(2.3, 4.3, -7.5), (2.3, 8.5, -7.5)]]
diff --git a/labs02/task06.py b/labs02/task06.py
index ff4a9d3..bdadb73 100644
--- a/labs02/task06.py
+++ b/labs02/task06.py
@@ -10,7 +10,21 @@ ma być zwracany napis "It's not a Big 'No!'".
 """
 
 def big_no(n):
-    pass
+    def test_special_cases(self):
+        """Testy przypadków szczególnych."""
+        self.assertEqual(big_no(0), "It's not a Big 'No!'")
+        self.assertEqual(big_no(1), "It's not a Big 'No!'")
+        self.assertEqual(big_no(2), "It's not a Big 'No!'")
+        self.assertEqual(big_no(4), "It's not a Big 'No!'")
+        self.assertEqual(big_no(5), "NOOOOO!")
+
+    def test_regular_cases(self):
+        """Testy dla zwykłych przypadków"""
+        self.assertEqual(big_no(6), "NOOOOOO!")
+        self.assertEqual(big_no(33), "N" + ("O" * 33) + "!")
+
+
+
 
 def tests(f):
     inputs = [[5], [6], [2]]
diff --git a/labs03/Podstawy 2.ipynb b/labs03/Podstawy 2.ipynb
index adf5795..53da94e 100644
--- a/labs03/Podstawy 2.ipynb	
+++ b/labs03/Podstawy 2.ipynb	
@@ -49,34 +49,22 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "slide"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "2\n",
-      "[1, 2, 3, 1, 2, 3]\n",
-      "123\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
-    "def dwojak(x): \n",
-    "    x *= 2\n",
-    "    return x\n",
+    "def dwojak(x): x *= 2\n",
     "    \n",
     "l = [1, 2, 3]\n",
     "s = \"123\"\n",
     "\n",
     "dwojak(l)\n",
     "dwojak(s)\n",
-    "print(dwojak(1))\n",
+    "\n",
     "print(l)\n",
     "print(s)"
    ]
@@ -116,28 +104,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "slide"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "[1, 2, 3, 1, 2, 3]\n",
-      "F: [1, 2, 3, 1, 2, 3]\n",
-      "[1, 2, 3]\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "def dwojak1(x): x *= 2\n",
-    "def dwojak2(x): \n",
-    "    x = x * 2\n",
-    "    print(\"F:\", x)\n",
+    "def dwojak2(x): x = x * 2\n",
     "\n",
     "l = [1,2, 3]\n",
     "dwojak1(l)\n",
@@ -150,47 +126,29 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "slide"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "[1, 2, 3]\n",
-      "[1, 2, 3, 4]\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "l = [1, 2, 3]\n",
-    "e = l[:]\n",
+    "e = l\n",
     "e.append(4)\n",
-    "print(l)\n",
-    "print(e)"
+    "print(l)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "slide"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "[[1], [1], [1]]\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "e = []\n",
     "f = [e for i in range(3)]\n",
@@ -214,39 +172,18 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 25,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "slide"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "(1, 'napis', [0])\n",
-      "3\n"
-     ]
-    },
-    {
-     "ename": "TypeError",
-     "evalue": "unhashable type: 'list'",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-25-2bd2fa17fbf5>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m      3\u001b[0m \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mt\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      4\u001b[0m \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mlen\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mt\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 5\u001b[0;31m \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m{\u001b[0m\u001b[0mt\u001b[0m\u001b[0;34m:\u001b[0m \u001b[0;32mNone\u001b[0m\u001b[0;34m}\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
-      "\u001b[0;31mTypeError\u001b[0m: unhashable type: 'list'"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
-    "t = (1, \"napis\", [])\n",
-    "t[-1].append(0)\n",
+    "t = (1, \"napis\", None)\n",
+    "elem = t[0]\n",
     "print(t)\n",
-    "print(len(t))\n",
-    "print({t: None})"
+    "print(len(t))"
    ]
   },
   {
@@ -262,29 +199,19 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 36,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "fragment"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "15\n",
-      "a == 1\n",
-      "b == (3, 4)\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "def suma(*args):\n",
     "    return sum(args)\n",
     "print(suma(1,2,3,4,5))\n",
     "\n",
-    "def greet_me(z=None,**kwargs):\n",
+    "def greet_me(**kwargs):\n",
     "    if kwargs is not None:\n",
     "        for key, value in kwargs.items():\n",
     "            print(\"%s == %s\" %(key,value))\n",
@@ -304,32 +231,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 38,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "fragment"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "97\n",
-      "a\n",
-      "98\n",
-      "b\n",
-      "99\n",
-      "c\n",
-      "100\n",
-      "d\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "def alfaRange(x, y):\n",
     "    for i in range(ord(x), ord(y)):\n",
-    "        print(i)\n",
     "        yield chr(i)\n",
     "\n",
     "for c in alfaRange('a', 'e'):\n",
@@ -349,74 +260,40 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 45,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "fragment"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "W Paryżu najlepsze kasztany są na placu Pigalle\n",
-      "Zuzanna lubi je tylko jesienią.\n",
-      "\n",
-      ">>\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "plik = open(\"haslo.txt\", 'r')\n",
     "for linia in plik.readlines():\n",
     "    print(linia.strip())\n",
     "print(plik.read())\n",
-    "print(\">>\")\n",
     "plik.close()"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 47,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "slide"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "W Paryżu najlepsze kasztany są na placu Pigalle\n",
-      "\n",
-      "Zuzanna lubi je tylko jesienią.\n",
-      "\n"
-     ]
-    },
-    {
-     "ename": "ValueError",
-     "evalue": "I/O operation on closed file.",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mValueError\u001b[0m                                Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-47-f06513c1bbec>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m      2\u001b[0m     \u001b[0;32mfor\u001b[0m \u001b[0mlinia\u001b[0m \u001b[0;32min\u001b[0m \u001b[0mplik\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mreadlines\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      3\u001b[0m         \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mlinia\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 4\u001b[0;31m \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mplik\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mread\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
-      "\u001b[0;31mValueError\u001b[0m: I/O operation on closed file."
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "with open(\"haslo.txt\", 'r') as plik:\n",
     "    for linia in plik.readlines():\n",
     "        print(linia)\n",
-    "print(plik.read())"
+    "# print(plik.read())"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 48,
+   "execution_count": null,
    "metadata": {
     "collapsed": true,
     "slideshow": {
@@ -457,22 +334,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 49,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "fragment"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "posix\n",
-      "Nazwa uzytkownika: tomaszd\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "import os\n",
     "print(os.name)\n",
@@ -483,31 +351,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 50,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "slide"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Counter({'o': 4, 'n': 4, 'a': 4, 'k': 3, 't': 3, 'y': 2, 'i': 2, 'c': 2, 'z': 2, 's': 1, 'p': 1, 'l': 1, 'ń': 1, 'w': 1, 'e': 1})\n"
-     ]
-    },
-    {
-     "data": {
-      "text/plain": [
-       "array([[ 1.,  3.,  4.,  5.]], dtype=float32)"
-      ]
-     },
-     "execution_count": 50,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
+   "outputs": [],
    "source": [
     "from collections import *\n",
     "print(Counter(\"konstantynopolitańczykowianeczka\"))\n",
@@ -544,23 +394,13 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 51,
+   "execution_count": null,
    "metadata": {
     "slideshow": {
      "slide_type": "fragment"
     }
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "What's your name?\n",
-      "Tomasz\n",
-      "Welcome home, Tomasz.\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "name = input(\"What's your name?\\n\")\n",
     "print(\"Welcome home, {}.\".format(name))"
diff --git a/labs04/zad2_lab4.py b/labs04/zad2_lab4.py
new file mode 100644
index 0000000..affa000
--- /dev/null
+++ b/labs04/zad2_lab4.py
@@ -0,0 +1,45 @@
+'''
+**ćwiczenie 2**
+Napisz prostą hierarchię klas:
+ * Klasa bazowa ``Employee``, która będzie zawierać informacje o imieniu i nazwisku pracownika. Ponadto każdy pracownik otrzyma numer ``id``, który będzie unikatowy.
+ Wykorzystaj do tego atrybut statyczny. Napisz metodę ``get_id``, która zwraca identyfikator pracownika.
+ * Klasy pochodna:  ``Recruiter``, która ma dodatkową mtodę ``recruit``, która jako parament przyjmuje obiekt ``Employee`` i zapisuje jego ``id`` w liście ``self.recruited``.
+ * Klasa pochodna ``Programmer``. Klasa ``Programmer`` ma przyjąć w konstruktorze podstawowe informacje (imię i nazwisko) oraz obiekt rekturera.
+ Ponadto stwórz  atrybut ``recruiter``, który będzie przechowywać ``id`` rekrutera.
+'''
+
+class Employee:
+    ID_COUNTER = 1000
+
+    def __init__(self, first_name, second_name):
+        self.first_name = first_name
+        self.second_name = second_name
+        self.id = Employee.ID_COUNTER
+        Employee.ID_COUNTER += 1
+
+    def get_id(self):
+        return self.id
+
+class Recruiter(Employee):
+    def __init__(self, first_name, second_name):
+        Employee.__init__(self, first_name, second_name)
+        self.recruited = []
+
+    def recruit(self, employee):
+        self.recruited.append(employee.get_id())
+
+
+class Programmer(Employee):
+    def __init__(self, first_name, second_name, recruiter):
+        Employee.__init__(self, first_name, second_name)
+        self.recruiter = recruiter.get_id()
+
+employee1 = Employee('John', 'Smith')
+print(employee1.get_id())
+employee2 = Employee('Bob', 'Marley')
+print(employee2.get_id())
+
+recruiter1 = Recruiter('Recruiter', 'Andy')
+recruiter1.recruit(employee1)
+
+programmer1 = Programmer('Programmer', 'Frank', recruiter1)
diff --git a/labs04/zad3_lab4.py b/labs04/zad3_lab4.py
new file mode 100644
index 0000000..eed2464
--- /dev/null
+++ b/labs04/zad3_lab4.py
@@ -0,0 +1,62 @@
+'''
+**ćwiczenie 3 (zadanie domowe) **
+Stwórz klasę ``Point``, która będzie reprezentować punkt w przestrzeni wielowymiarowej:
+ * Konstruktor ma przyjąc tylko 1 parametr: listę współrzednych. Wykorzystaj funkcję z pierwszego zadania, żeby sprawdzić, czy lista zawiera wyłącznie liczby.
+ * Napisz metodę add, która dida dwa punkty (dwa wektory) po współrzędnych i zwróci obiekt typu ``Punkt``. Zaimplementuj własny wyjątek ``DimensionError``, który zostaje wyrzucony, jeżeli dodawany punkt ma inny wymiar.
+ * Napisz metodę ``to\_string``, która zwróci łancuch znakowy, który w czytelny sposób przedstawi punkt.
+ * Napisz metodę __len__, która zwróci liczbę współrzędnych punktu. Zobacz, czy możesz teraz wywołać funkcję len na obiekcie typy punkt.
+ * Napisz metodę __str__, która bedzie działać dokładnie tak samo jak metoda ``to_string``. Wyświetl obiekt typy Point korzystając z funkcji print.
+'''
+
+
+class DimensionError(Exception):
+    pass
+
+
+def validate_list(list_arg):
+    return sum([not (type(element) is int or type(element) is float) for element in list_arg]) == 0
+
+
+class Point:
+    def __init__(self, coords):
+        if validate_list(coords):
+            self.coords = coords[:]
+        else:
+            self.coords = [0]
+
+    def add(self, point_right):
+        n = len(self.coords)
+
+        if n != len(point_right):
+            raise DimensionError("Wymiary punktów się nie zgadzają.")
+
+        return Point([self.coords[i] + point_right.coords[i] for i in range(n)])
+
+    def to_string(self):
+        return '(' + ', '.join(map(str, self.coords)) + ')'
+
+    def __len__(self):
+        return len(self.coords)
+
+    def __str__(self):
+        return self.to_string()
+
+
+# testowanie
+
+p1 = Point([1, 2, 3])
+p2 = Point([4, 5, 6])
+
+print(p1.to_string())
+print(p2.to_string())
+
+print(str(p1.add(p2)))
+print(len(p1))
+print(Point(['1']))
+
+try:
+    p1.add(Point([1]))
+except:
+    print('wyjątek')
+
+