{
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  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Week 5 Notes - Functions"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Built-in functions"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "8\n"
     ]
    }
   ],
   "source": [
    "a = pow(2,3)\n",
    "print(a)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(2+3j)\n"
     ]
    }
   ],
   "source": [
    "b = complex(2,3)\n",
    "print(b)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Functions that are part of Python's Standard Library"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-0.9589242746631385\n"
     ]
    }
   ],
   "source": [
    "from math import sin\n",
    "\n",
    "c = sin(5)\n",
    "print(c)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Functions that are part of external packages"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-0.9589242746631385\n"
     ]
    }
   ],
   "source": [
    "import numpy as np\n",
    "\n",
    "d = np.sin(5)\n",
    "print(d)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Positional Arguments"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(5+3j)\n"
     ]
    }
   ],
   "source": [
    "f = complex(5,3)\n",
    "print(f)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Keyword Arguments"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(5+3j)\n"
     ]
    }
   ],
   "source": [
    "g = complex(imag=3,real=5)\n",
    "print(g)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Define a function in Python"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [],
   "source": [
    "def plus3(n):\n",
    "    out = n + 3\n",
    "    return out"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "5\n"
     ]
    }
   ],
   "source": [
    "h = plus3(2)\n",
    "print(h)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [],
   "source": [
    "def tri_area(b,h):\n",
    "    area = 0.5*b*h\n",
    "    return area"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "5.0\n"
     ]
    }
   ],
   "source": [
    "k = tri_area(2,5)\n",
    "print(k)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Create a function that calculates the distance an object will fall in a certain amount of time\n",
    "# d = 0.5 * g * t**2\n",
    "# on earth g=9.81 m/s^2\n",
    "# on the mooon g=1.62 m/s^2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [],
   "source": [
    "def fall_dist(t,g=9.81):\n",
    "    d = 0.5*g*t**2\n",
    "    return d"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "44.145\n"
     ]
    }
   ],
   "source": [
    "# calculate the distance an object falls on earth in 3 seconds\n",
    "m = fall_dist(3)\n",
    "print(m)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "7.290000000000001\n"
     ]
    }
   ],
   "source": [
    "# calculate the distnace an object falls on the moon in 3 seconds\n",
    "n = fall_dist(3,g=1.62)\n",
    "print(n)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Including documentation and help in your functions"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Help on built-in function pow in module builtins:\n",
      "\n",
      "pow(x, y, z=None, /)\n",
      "    Equivalent to x**y (with two arguments) or x**y % z (with three arguments)\n",
      "    \n",
      "    Some types, such as ints, are able to use a more efficient algorithm when\n",
      "    invoked using the three argument form.\n",
      "\n"
     ]
    }
   ],
   "source": [
    "help(pow)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Help on function fall_dist in module __main__:\n",
      "\n",
      "fall_dist(t, g=9.81)\n",
      "\n"
     ]
    }
   ],
   "source": [
    "help(fall_dist)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [],
   "source": [
    "def fall_dist(t,g=9.81):\n",
    "    \"\"\"\n",
    "    The fall_dist() function calculates the distance an object falls in a given amount of time\n",
    "    \n",
    "    input: time, int or float and optionally g= int, or float for the acceleration due to gravity, default g=9.81\n",
    "    output: fall distance, int or float\n",
    "    \n",
    "        m = fall_dist(3)\n",
    "        print(m)\n",
    "        \n",
    "        44.145\n",
    "        \n",
    "        n = fall_dist(3,g=1.62)\n",
    "        print(n)\n",
    "    \n",
    "        7.290000000000001\n",
    "    \n",
    "    \"\"\"\n",
    "    d = 0.5*g*t**2\n",
    "    return d"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Help on function fall_dist in module __main__:\n",
      "\n",
      "fall_dist(t, g=9.81)\n",
      "    The fall_dist() function calculates the distance an object falls in a given amount of time\n",
      "    \n",
      "    input: time, int or float and optionally g= int, or float for the acceleration due to gravity, default g=9.81\n",
      "    output: fall distance, int or float\n",
      "    \n",
      "        m = fall_dist(3)\n",
      "        print(m)\n",
      "        \n",
      "        44.145\n",
      "        \n",
      "        n = fall_dist(3,g=1.62)\n",
      "        print(n)\n",
      "    \n",
      "        7.290000000000001\n",
      "\n"
     ]
    }
   ],
   "source": [
    "help(fall_dist)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Define a function in an external file, import it and run it"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      " Volume in drive C is Windows\n",
      " Volume Serial Number is B899-AB94\n",
      "\n",
      " Directory of C:\\Users\\student\\Desktop\n",
      "\n",
      "10/22/2019  02:37 PM    <DIR>          .\n",
      "10/22/2019  02:37 PM    <DIR>          ..\n",
      "10/22/2019  02:02 PM    <DIR>          .ipynb_checkpoints\n",
      "10/22/2019  01:32 PM             1,457 Kaltura Capture.lnk\n",
      "05/13/2016  01:33 PM               210 MSDS Online.url\n",
      "10/22/2019  02:37 PM                57 myfuncs.py\n",
      "08/01/2018  04:14 PM    <DIR>          Safety Information\n",
      "10/22/2019  02:32 PM             9,322 Week5_notes_functions.ipynb\n",
      "               4 File(s)         11,046 bytes\n",
      "               4 Dir(s)  321,217,835,008 bytes free\n"
     ]
    }
   ],
   "source": [
    "%ls"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "5"
      ]
     },
     "execution_count": 29,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import myfuncs\n",
    "\n",
    "myfuncs.plus2(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "5"
      ]
     },
     "execution_count": 30,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "from myfuncs import plus2\n",
    "\n",
    "plus2(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "5"
      ]
     },
     "execution_count": 32,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import myfuncs\n",
    "\n",
    "dir(myfuncs)\n",
    "myfuncs.plus2(3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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