Python Random Numbers Module.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Python Random Numbers Module\n",
    "[Official Documentation](https://docs.python.org/3/library/random.html)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import random"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### randint\n",
    "Gives you a random integer between from and to values, inclusive."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2 2 3 1 1 2 0 2 3 2 0 0 2 2 0 3 3 2 1 2 3 0 2 2 2 "
     ]
    }
   ],
   "source": [
    "for i in range (25):\n",
    "    print(random.randint(0, 3), end=' ')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### randrange\n",
    "Works similar to the range function -- gives you a random number between from and to-1, with optional step.  \n",
    "From defaults to 0 if only 1 argument is given.  \n",
    "Step defaults to 1 if only 2 arguments are given."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 38,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "25\n",
      "3 6 6 6 6 3 3 3 0 0 6 6 3 0 6 0 3 0 6 6 6 6 3 3 6 "
     ]
    }
   ],
   "source": [
    "print(random.randrange(100))\n",
    "\n",
    "for i in range (25):\n",
    "    print(random.randrange(0, 9, 3), end=' ')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### choice\n",
    "Returns one randomly chosen item from a sequence (list, tuple or string). Works for lists/tuples of integers, floats, strings or other objects. "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "9\n",
      "Roby\n",
      "Darby\n",
      "Washington\n",
      "Hampton\n"
     ]
    }
   ],
   "source": [
    "print(random.choice([3, 5, 7, 9, 11]))\n",
    "\n",
    "names = ['Roby', 'Matthews', 'Washington', 'Darby', 'Hampton']\n",
    "for i in range(4):\n",
    "    print(random.choice(names))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-\n",
      "a  c  e  b  b  a  e  d  c  c  "
     ]
    }
   ],
   "source": [
    "print(random.choice('bunch-of-letters'))\n",
    "\n",
    "material = 'brocade'\n",
    "for i in range(10):\n",
    "    print(random.choice(material), end='  ')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### choices\n",
    "Just like choice, but returns a list of n random choices, with replacement, so each pick is from the full sequence."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[9, 5, 3, 6, 5, 6, 5, 3, 1, 5, 10, 1, 4, 4, 10]\n",
      "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]\n"
     ]
    }
   ],
   "source": [
    "numbers = [n+1 for n in range(10)]\n",
    "my_picks = random.choices(numbers, k=15)\n",
    "print(my_picks)\n",
    "print(numbers)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['Darby', 'Hampton']\n"
     ]
    }
   ],
   "source": [
    "names = ['Roby', 'Matthews', 'Washington', 'Darby', 'Hampton']\n",
    "print(random.choices(names, k=2))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "You can also add weights if you want some items to have a better chance of being picked. Here, 1 is 4x more likely than 4 to be picked."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[2, 1, 3, 4, 1, 1, 1, 3, 2, 2, 2, 4, 2, 1, 1, 3, 2, 3, 1, 3]\n"
     ]
    }
   ],
   "source": [
    "numbers = [1,2,3,4]\n",
    "my_picks = random.choices(numbers, weights=[4,3,2,1], k=20)\n",
    "print(my_picks)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Use random.choices to generate random passwords  \n",
    "First we pick a list of 8 random numbers between a and z on the ascii table, then we convert the numbers to ascii letters, then join them into a string."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[100, 109, 104, 100, 103, 102, 118, 121]\n",
      "dmhdgfvy\n"
     ]
    }
   ],
   "source": [
    "picks = random.choices(range(ord('a'),ord('z')), k=8)\n",
    "print(picks)\n",
    "picks = [chr(i) for i in picks]\n",
    "print(''.join(picks))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Here's a random password generator that uses all upper and lower case letters and numbers."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 46,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Z81Hw3uk\n"
     ]
    }
   ],
   "source": [
    "import string\n",
    "all_chars = string.ascii_lowercase + string.ascii_uppercase + string.digits\n",
    "pw = ''.join(random.choices(all_chars, k=8))\n",
    "print(pw)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### sample\n",
    "Just like choices, but without replacement.  \n",
    "Useful for picking lottery winners or bingo numbers.  \n",
    "Returned list is in the order they were picked."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 49,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['green', 'pink']\n"
     ]
    }
   ],
   "source": [
    "colors = ['red', 'blue', 'green', 'aqua', 'pink', 'black']\n",
    "picks = random.sample(colors, k=2)\n",
    "print(picks)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Using the range function as an argument will not give you any duplicate picks."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 35,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[18, 38, 20, 50, 1]\n"
     ]
    }
   ],
   "source": [
    "picks = random.sample(range(1,51), k=5)\n",
    "print(picks)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### shuffle\n",
    "Shuffle any sequence into random order.  \n",
    "This is an in-place shuffle, and it doesn't return anything."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 50,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1, 2, 3, 4, 5, 6, 7, 8]\n",
      "None\n",
      "[2, 6, 8, 1, 4, 7, 5, 3]\n"
     ]
    }
   ],
   "source": [
    "numbers = [1, 2, 3, 4, 5, 6, 7, 8]\n",
    "print(numbers)\n",
    "print(random.shuffle(numbers))\n",
    "\n",
    "random.shuffle(numbers)\n",
    "print(numbers)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "----"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### random.random()\n",
    "Random floating point values between 0.0 and 1.0."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0.8424897774160051\n",
      "0.9016594664191279\n",
      "0.5162849368345925\n",
      "0.021852081927422384\n",
      "0.5740618908246983\n",
      "0.6539291129848911\n"
     ]
    }
   ],
   "source": [
    "print(random.random())\n",
    "\n",
    "for i in range(5):\n",
    "    print(random.random())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### uniform (from, to)\n",
    "Random float between a range of values"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 52,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2.5032833557221568\n",
      "10.31258224982709\n",
      "9.431820659293221\n",
      "10.4390639618008\n",
      "9.6906814789157\n",
      "10.559354593909362\n"
     ]
    }
   ],
   "source": [
    "print(random.uniform(2.1, 4.3))\n",
    "\n",
    "for i in range(5):\n",
    "    print(random.uniform(9.4, 10.7))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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