Python_Intro_Part3_Conditions.ipynb

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    "___\n",
    "\n",
    "<a href='https://virasec.ir'> <img src='viraacademy-Logo.png' /></a>\n",
    "___\n",
    "\n",
    "\n",
    "# Python If ... Else"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Python Conditions and If statements\n",
    "\n",
    "Python supports the usual logical conditions from mathematics:\n",
    "\n",
    "Equals: a == b\n",
    "    \n",
    "Not Equals: a != b\n",
    "    \n",
    "Less than: a < b\n",
    "    \n",
    "Less than or equal to: a <= b\n",
    "    \n",
    "Greater than: a > b\n",
    "    \n",
    "Greater than or equal to: a >= b\n",
    "    "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "b is greater than a\n"
     ]
    }
   ],
   "source": [
    "#If statement:\n",
    "\n",
    "a = 33\n",
    "b = 200\n",
    "if b > a:\n",
    "  print(\"b is greater than a\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Indentation"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "ename": "IndentationError",
     "evalue": "expected an indented block (<ipython-input-16-7789e316117b>, line 6)",
     "output_type": "error",
     "traceback": [
      "\u001b[1;36m  File \u001b[1;32m\"<ipython-input-16-7789e316117b>\"\u001b[1;36m, line \u001b[1;32m6\u001b[0m\n\u001b[1;33m    print(\"b is greater than a\") # you will get an error\u001b[0m\n\u001b[1;37m        ^\u001b[0m\n\u001b[1;31mIndentationError\u001b[0m\u001b[1;31m:\u001b[0m expected an indented block\n"
     ]
    }
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   "source": [
    "#If statement, without indentation (will raise an error):\n",
    "\n",
    "a = 33\n",
    "b = 200\n",
    "if b > a:\n",
    "print(\"b is greater than a\") # you will get an error"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Elif\n",
    "\n",
    "The elif keyword is pythons way of saying \"if the previous conditions were not true, then try this condition\"."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "a and b are equal\n"
     ]
    }
   ],
   "source": [
    "a = 33\n",
    "b = 33\n",
    "if b > a:\n",
    "  print(\"b is greater than a\")\n",
    "elif a == b:\n",
    "  print(\"a and b are equal\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Else\n",
    "The else keyword catches anything which isn't caught by the preceding conditions."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "a is greater than b\n"
     ]
    }
   ],
   "source": [
    "a = 200\n",
    "b = 33\n",
    "if b > a:\n",
    "  print(\"b is greater than a\")\n",
    "elif a == b:\n",
    "  print(\"a and b are equal\")\n",
    "else:\n",
    "  print(\"a is greater than b\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "b is not greater than a\n"
     ]
    }
   ],
   "source": [
    "a = 200\n",
    "b = 33\n",
    "if b > a:\n",
    "  print(\"b is greater than a\")\n",
    "else:\n",
    "  print(\"b is not greater than a\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Short Hand If"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "a is greater than b\n"
     ]
    }
   ],
   "source": [
    "if a > b: print(\"a is greater than b\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Short Hand If ... Else"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "B\n"
     ]
    }
   ],
   "source": [
    "a = 2\n",
    "b = 330\n",
    "print(\"A\") if a > b else print(\"B\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## AND"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Both conditions are True\n"
     ]
    }
   ],
   "source": [
    "a = 200\n",
    "b = 33\n",
    "c = 500\n",
    "if a > b and c > a:\n",
    "  print(\"Both conditions are True\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# OR"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "At least one of the conditions is True\n"
     ]
    }
   ],
   "source": [
    "b = 33\n",
    "c = 500\n",
    "if a > b or a > c:\n",
    "  print(\"At least one of the conditions is True\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Nested If"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Above ten,\n",
      "and also above 20!\n"
     ]
    }
   ],
   "source": [
    "x = 41\n",
    "\n",
    "if x > 10:\n",
    "  print(\"Above ten,\")\n",
    "  if x > 20:\n",
    "    print(\"and also above 20!\")\n",
    "  else:\n",
    "    print(\"but not above 20.\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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