Looping_Statements.ipynb

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   "source": [
    "# Looping Statements\n",
    "Execute a group of lines repeatedly.\n",
    "\n",
    "Finite looping is the best practice in programming but infinite looping are done because they are easy at times.\n",
    "\n",
    "1. For loop\n",
    "2. While loop\n",
    "\n",
    "Looping variables are generally named i, j, and k, while other names can be used."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 1. For loop:\n",
    "General and most common finite looping.\n",
    "\n",
    "For loop is used to iterate through a sequence or iterator.\n",
    "Lists, tuple, dictionary and string.\n",
    "Syntax:\n",
    "```python\n",
    "for value in iterable:  \n",
    "    Statements\n",
    "```"
   ]
  },
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    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "2\n",
      "3\n",
      "4\n",
      "5\n"
     ]
    }
   ],
   "source": [
    "# Example 1\n",
    "l = [1, 2, 3, 4, 5]\n",
    "for i in l:\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "H\n",
      "e\n",
      "l\n",
      "l\n",
      "o\n"
     ]
    }
   ],
   "source": [
    "# Example 2\n",
    "s = 'Hello'\n",
    "for char in s:\n",
    "    print(char)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "ename": "TypeError",
     "evalue": "'int' object is not iterable",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
      "\u001b[1;32m<ipython-input-3-e4b54106f29e>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m\u001b[0m\n\u001b[0;32m      1\u001b[0m \u001b[0mnum\u001b[0m \u001b[1;33m=\u001b[0m \u001b[1;36m10\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m----> 2\u001b[1;33m \u001b[1;32mfor\u001b[0m \u001b[0mi\u001b[0m \u001b[1;32min\u001b[0m \u001b[0mnum\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m      3\u001b[0m     \u001b[0mprint\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mnum\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
      "\u001b[1;31mTypeError\u001b[0m: 'int' object is not iterable"
     ]
    }
   ],
   "source": [
    "# Error for int\n",
    "num = 10\n",
    "for i in num:\n",
    "    print(num)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Range function:\n",
    "Used to create an sequence/object from *start* to *stop* in *steps*\n",
    "\n",
    "Syntax: \n",
    "```python\n",
    "range(stop)  \n",
    "range(start, stop, [step=1])\n",
    "```"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1 2 3 4 5 6 7 8 9\n",
      "0 1 2 3 4 5 6 7 8 9\n"
     ]
    }
   ],
   "source": [
    "# Output of range\n",
    "print(*range(1, 10))\n",
    "print(*range(10))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "1\n",
      "2\n",
      "3\n",
      "4\n",
      "5\n",
      "6\n",
      "7\n",
      "8\n",
      "9\n"
     ]
    }
   ],
   "source": [
    "#Example 1\n",
    "for i in range(10):\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "2\n",
      "4\n",
      "6\n",
      "8\n",
      "10\n",
      "12\n",
      "14\n",
      "16\n",
      "18\n"
     ]
    }
   ],
   "source": [
    "#Example 2\n",
    "for i in range(0, 20, 2):\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "1\n",
      "2\n",
      "3\n",
      "4\n",
      "5\n",
      "6\n",
      "7\n",
      "8\n",
      "9\n"
     ]
    }
   ],
   "source": [
    "#Example 3\n",
    "for i in range(0, 10, 1):\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 2. While loops:\n",
    "Most common for infinite looping.\n",
    "Used to work on numbers or variable length iterables.\n",
    "Preferred for variable conditions\n",
    "\n",
    "Syntax: \n",
    "```python\n",
    "while condition:  \n",
    "    Statements\n",
    "```"
   ]
  },
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   "execution_count": 1,
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     "text": [
      "1\n",
      "2\n",
      "3\n",
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      "5\n",
      "6\n",
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      "8\n",
      "9\n",
      "10\n"
     ]
    }
   ],
   "source": [
    "# Example 1:\n",
    "i = 1\n",
    "while i<=10:\n",
    "    print(i)\n",
    "    i+=1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
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      "100\n"
     ]
    }
   ],
   "source": [
    "# Example 2 using infinite looping\n",
    "i = 1\n",
    "while True:\n",
    "    print(i)\n",
    "    if i==100:\n",
    "        break\n",
    "    i+=1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Loop Control statements:\n",
    "\n",
    "Control the execution of the loop\n",
    "\n",
    "1. Break\n",
    "2. Continue\n",
    "3. Pass"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### 1. break\n",
    "\n",
    "This statement ends the loop when encountered.\n",
    "\n",
    "#### 2. continue\n",
    "\n",
    "Skips the loop execution when encountered.\n",
    "\n",
    "#### 3. pass\n",
    "No change to loop\n",
    "Used when there no statements currently present"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "1\n",
      "1\n",
      "1\n",
      "2\n",
      "2\n",
      "2\n",
      "2\n",
      "3\n",
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      "3\n",
      "3\n",
      "4\n",
      "4\n",
      "4\n",
      "4\n"
     ]
    }
   ],
   "source": [
    "i = 1\n",
    "while i<5:\n",
    "    j=0\n",
    "    while True:\n",
    "        print(i)\n",
    "        j+=1 # j = j+1\n",
    "        if j==4:\n",
    "            break\n",
    "    i+=1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
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      "3\n",
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      "10\n",
      "11\n"
     ]
    }
   ],
   "source": [
    "#Example\n",
    "i = 0\n",
    "while i<11:\n",
    "    i+=1\n",
    "    if i==5: continue\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1\n",
      "3\n",
      "5\n",
      "7\n",
      "9\n"
     ]
    }
   ],
   "source": [
    "#Example 1\n",
    "for i in range(10):\n",
    "    if i%2 == 0:\n",
    "        pass\n",
    "    else: print(i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "Odd\n",
      "1\n",
      "2\n",
      "Odd\n",
      "3\n",
      "4\n",
      "Odd\n",
      "5\n",
      "6\n",
      "Odd\n",
      "7\n",
      "8\n",
      "Odd\n",
      "9\n"
     ]
    }
   ],
   "source": [
    "#Example 2\n",
    "for i in range (10):\n",
    "    if i%2==0: pass\n",
    "    else: print('Odd')\n",
    "    print(i)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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