example

bonus_example.ipynb

@@ -0,0 +1,275 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Matching Characters"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Overview"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Individual characters can be matched in regular expressions simply by indicating the characters as a pattern. A special character, `.`, is used as a wildcard to indicate that any character which is not a newline can be matched instead. Some special characters, such as `\\`, `(`, and `)` might need to be escaped in order to be matched. To escape a character put a `\\` in front of it."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Examples\n",
+    "In these examples we will use the text of article five of the United States Constitution, as found on wikipedia at https://en.wikipedia.org/wiki/Article_Five_of_the_United_States_Constitution."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Example One"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "['the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the',\n",
+       " 'the']"
+      ]
+     },
+     "execution_count": 13,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "text = r\"\"\"\n",
+    "The Congress, whenever two thirds of both houses shall deem it necessary, shall propose amendments to this \n",
+    "Constitution, or, on the application of the legislatures of two thirds of the several states, shall call a \n",
+    "convention for proposing amendments, which, in either case, shall be valid to all intents and purposes, as \n",
+    "part of this Constitution, when ratified by the legislatures of three fourths of the several states, or by \n",
+    "conventions in three fourths thereof, as the one or the other mode of ratification may be proposed by the \n",
+    "Congress; provided that no amendment which may be made prior to the year one thousand eight hundred and \n",
+    "eight shall in any manner affect the first and fourth clauses in the ninth section of the first article; \n",
+    "and that no state, without its consent, shall be deprived of its equal suffrage in the Senate.\"\"\"\n",
+    "\n",
+    "# To match all instances of the word \"the\" we just set that string to be the pattern\n",
+    "pattern=r\"the\"\n",
+    "\n",
+    "# We then import the python regular expression library\n",
+    "import re\n",
+    "\n",
+    "# And we look for all instances of this pattern\n",
+    "re.findall(pattern, text)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Example Two"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 14,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[' two ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' two ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ',\n",
+       " ' the ']"
+      ]
+     },
+     "execution_count": 14,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "# To match all ithree letter words that begin with the letter \"t\" we just set our pattern to be a \"t\" followed\n",
+    "# by two wildcard characters and both preceded and followed by space characters, which indicate the beginning\n",
+    "# and ends of a word. Note that this won't work for words which end a sentence, as punctuation isn't a space, \n",
+    "# but we can deal with that in a different manner\n",
+    "pattern=r\" t.. \"\n",
+    "\n",
+    "# And we look for all instances of this pattern\n",
+    "re.findall(pattern, text)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Problems\n",
+    "In these problems you will use text from the Canadian Charter of Rights and Freedoms section 2 from wikipedia https://en.wikipedia.org/wiki/Section_2_of_the_Canadian_Charter_of_Rights_and_Freedoms."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Problem 1\n",
+    "Count the number of freedoms listed (they are enumerated in parentheses). Return a single number."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 15,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "text=r\"\"\"\n",
+    "2. Everyone has the following fundamental freedoms:\n",
+    "(a) freedom of conscience and religion;\n",
+    "(b) freedom of thought, belief, opinion and expression, including freedom of the press and other media of communication;\n",
+    "(c) freedom of peaceful assembly; and\n",
+    "(d) freedom of association.\n",
+    "\"\"\"\n",
+    "\n",
+    "# Your code goes here"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 18,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "4\n"
+     ]
+    }
+   ],
+   "source": [
+    "# Solution\n",
+    "\n",
+    "# First we import the python re module\n",
+    "import re\n",
+    "\n",
+    "# In this pattern we want to match any single character in paretheses followed by a space. Note that we have\n",
+    "# to escape the parentheses.\n",
+    "pattern=r\"\\(.\\) \"\n",
+    "\n",
+    "# Now we just print the length of that list\n",
+    "print(len(re.findall(pattern,text)))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Problem 2\n",
+    "How many times is a word beginning with the term \"free\" mentioned in this section of the document? Return a single number."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 19,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "6\n"
+     ]
+    }
+   ],
+   "source": [
+    "# Solution\n",
+    "\n",
+    "# In this pattern we want to match just the term \"free\" with a space in front of it. This wouldn't catch words\n",
+    "# that started a sentence or paragraph as they might not be preceeded by a space (e.g. the start of a new \n",
+    "# line) and they might have different capitalization.\n",
+    "pattern=r\" free\"\n",
+    "\n",
+    "# Now we just print the length of that list\n",
+    "print(len(re.findall(pattern,text)))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Reuse"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "I authorize that this work may be used in further iterations of this or other classes with or without attribution in order to help people learn regex."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "I do not authorize this work to be used in further iterations of this or other classes."
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.7.3"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}