matching.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Student allocation to projects\n",
    "\n",
    "## Getting started\n",
    "Create 2 csv files or amend them with actual data\n",
    "- `student_preferences.csv` with 1 + number of preferences columns: student, preference1, preference2, ..., preferenceN\n",
    "- `project_capacities.csv` with 3 columns: project, capacity, supervisor\n",
    "\n",
    "Then run every cell, the output are two csv files\n",
    "- `matching_student.csv` for a student focused view with 2 columns: student, project allocated, preference rank of allocation, list of preferences\n",
    "- `matching_project.csv` for a project focused view with 4 columns: project, list of student allocated, capacity, supervisor\n",
    "\n",
    "## Other functions\n",
    "- `check_matching` checks the validity\n",
    "- `shuffle_students` randomly moves the order of the student. The order of students will affect the allocations, the student at the top will get largest priority of their choice of projects. They will, by definition, get their first choice."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd\n",
    "import numpy as np\n",
    "\n",
    "# Define student and project classes\n",
    "class Student:\n",
    "    def __init__(self, id, preferences):\n",
    "        self.id = id\n",
    "        self.preferences = preferences\n",
    "        self.matched_project = None\n",
    "        self.rank_choice = 1 # 1 indexed for readability\n",
    "\n",
    "class Project:\n",
    "    def __init__(self, id, capacity):\n",
    "        self.id = id\n",
    "        self.capacity = capacity\n",
    "        self.matched_students = []\n",
    "        self.applicant_students = []\n",
    "\n",
    "# Define functions to help algorithm\n",
    "def assign_student_to_project(student, project):\n",
    "    project.matched_students.append(student)\n",
    "    student.matched_project = project\n",
    "\n",
    "def remove_student_from_project(student, project):\n",
    "    project.matched_students.remove(student)\n",
    "    student.matched_project = None\n",
    "\n",
    "# Function to check validity of matching\n",
    "def check_matching(students, projects):\n",
    "    # check no student is matched to more than one project\n",
    "    for s in students:\n",
    "        if s.matched_project is not None:\n",
    "            for p in projects:\n",
    "                if p.id != s.matched_project.id and p == s.matched_project:\n",
    "                    print(f\"Major Warning - Student {s.id} is matched to multiple projects\")\n",
    "                    return False\n",
    "            \n",
    "    # check no project is matched to more than its capacity\n",
    "    for p in projects:\n",
    "        if len(p.matched_students) > p.capacity:\n",
    "            print(f\"Major Warning - Project {p.id} is matched to more students than its capacity\")\n",
    "            return False\n",
    "        \n",
    "    # warning - check if projects were preferred by students\n",
    "    for s in students:\n",
    "        if s.matched_project is not None and s.matched_project.id not in s.preferences:\n",
    "            print(f\"Minor Warning - Student {s.id} is matched to a project they did not prefer\")\n",
    "    \n",
    "    # warning - check any unassigned students\n",
    "    if any(s.matched_project is None for s in students):\n",
    "        print(f\"Minor Warning - Some students are not matched to any project\")\n",
    "        \n",
    "    # valid\n",
    "    print(\"Matching is valid\")\n",
    "    return True\n",
    "\n",
    "# Function to shuffle students\n",
    "def shuffle_students(students):\n",
    "    np.random.shuffle(students)\n",
    "\n",
    "# rate matching\n",
    "def rate_matching(students):\n",
    "    score = 0\n",
    "    for s in students:\n",
    "        if s.matched_project is not None:\n",
    "            score += 10 * s.rank_choice **-2\n",
    "    return score\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Gale-Shapley Algorithm implementation\n",
    "def gale_shapley(students, projects, n_prefs=None):\n",
    "    # By default, use all preferences\n",
    "    if n_prefs is None:\n",
    "        n_prefs = len(students[0].preferences)\n",
    "\n",
    "    # Initialize all students and projects as unmatched\n",
    "    for student in students:\n",
    "        student.matched_project = None\n",
    "    for project in projects:\n",
    "        project.matched_students = []\n",
    "\n",
    "    # Create a dictionary to easily access projects by their id\n",
    "    project_dict = {p.id: p for p in projects}\n",
    "\n",
    "    # Continue until all students have proposed to all their preferences\n",
    "    unconsidered_students = students.copy()\n",
    "    round_count = 0\n",
    "\n",
    "    while unconsidered_students and round_count < (len(students) * len(projects)):\n",
    "        round_count += 1\n",
    "        \n",
    "        for student in unconsidered_students.copy():\n",
    "            if student.rank_choice <= min(n_prefs, len(student.preferences)):\n",
    "                # Student proposes to their preference\n",
    "                project_id = student.preferences[student.rank_choice - 1]\n",
    "                project = project_dict[project_id]\n",
    "                \n",
    "                if project.capacity == 0:\n",
    "                    # Project is removed, move to next preference\n",
    "                    student.rank_choice += 1\n",
    "                elif len(project.matched_students) < project.capacity:\n",
    "                    # Project has capacity, accept the student\n",
    "                    assign_student_to_project(student, project)\n",
    "                    unconsidered_students.remove(student)\n",
    "                else:\n",
    "                    # Project is at capacity, compare with current matches\n",
    "                    # The student with the lowest rank choice (highest preference) is the preferred student\n",
    "                    # e.g. studentA.rank_choice = 1, studentB.rank_choice = 2, studentA is preferred\n",
    "                    worst_match = max(project.matched_students, key=lambda s: s.rank_choice)\n",
    "                    if student.rank_choice < worst_match.rank_choice:\n",
    "                        # New student is preferred, swap\n",
    "                        remove_student_from_project(worst_match, project)\n",
    "                        assign_student_to_project(student, project)\n",
    "                        unconsidered_students.remove(student)\n",
    "                        unconsidered_students.append(worst_match)\n",
    "                    else:\n",
    "                        # Student is rejected, move to next preference\n",
    "                        student.rank_choice += 1\n",
    "            else:\n",
    "                # Student has proposed to all preferences, remove from unconsidered_students\n",
    "                student.rank_choice = 0\n",
    "                unconsidered_students.remove(student)\n",
    "\n",
    "    return students, projects\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Example data - using csv\n",
    "\n",
    "student_preferences = pd.read_csv(\"student_preferences.csv\")\n",
    "# N+1 columns: student, preference1, preference2, ..., preferenceN\n",
    "\n",
    "project_capacities = pd.read_csv(\"project_capacities.csv\")\n",
    "# 3 columns: project, capacity, supervisor\n",
    "\n",
    "\n",
    "students = []\n",
    "projects = []\n",
    "\n",
    "for index, row in student_preferences.iterrows():\n",
    "    students.append(Student(row[\"student\"], row[1:].tolist()))\n",
    "\n",
    "for index, row in project_capacities.iterrows():\n",
    "    projects.append(Project(row[\"project\"], row[\"capacity\"]))\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "# ######################\n",
    "# ## Make change here ##\n",
    "# ######################\n",
    "# # Run the optimal seed search using `seed_search_par.py`. Set the optimal seed here.\n",
    "\n",
    "# # set optimal seed here\n",
    "# optimize_seed = 8001\n",
    "\n",
    "# np.random.seed(optimize_seed)\n",
    "# shuffle_students(students)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "==========\n",
      "Student Assignments:\n",
      "Student 1 matched to Project Project1 with rank choice 1\n",
      "Student 2 matched to Project Project10 with rank choice 1\n",
      "Student 3 matched to Project Project4 with rank choice 1\n",
      "Student 4 matched to Project Project12 with rank choice 1\n",
      "Student 5 matched to Project Project11 with rank choice 1\n",
      "Student 6 matched to Project Project3 with rank choice 1\n",
      "Student 7 matched to Project Project21 with rank choice 2\n",
      "Student 8 matched to Project Project14 with rank choice 1\n",
      "Student 9 matched to Project Project6 with rank choice 1\n",
      "Student 10 matched to Project Project19 with rank choice 1\n",
      "Student 11 matched to Project Project20 with rank choice 2\n",
      "Student 12 matched to Project Project5 with rank choice 1\n",
      "Student 13 matched to Project Project5 with rank choice 1\n",
      "Student 14 matched to Project Project20 with rank choice 5\n",
      "Student 15 matched to Project Project7 with rank choice 1\n",
      "Student 16 matched to Project None with rank choice 0\n",
      "Student 17 matched to Project Project13 with rank choice 1\n",
      "Student 18 matched to Project None with rank choice 0\n",
      "Student 19 matched to Project Project2 with rank choice 1\n",
      "Student 20 matched to Project Project22 with rank choice 2\n",
      "\n",
      "Project Assignments:\n",
      "Project Project1 matched to students: [1]\n",
      "Project Project2 matched to students: [19]\n",
      "Project Project3 matched to students: [6]\n",
      "Project Project4 matched to students: [3]\n",
      "Project Project5 matched to students: [12, 13]\n",
      "Project Project6 matched to students: [9]\n",
      "Project Project7 matched to students: [15]\n",
      "Project Project8 matched to students: []\n",
      "Project Project9 matched to students: []\n",
      "Project Project10 matched to students: [2]\n",
      "Project Project11 matched to students: [5]\n",
      "Project Project12 matched to students: [4]\n",
      "Project Project13 matched to students: [17]\n",
      "Project Project14 matched to students: [8]\n",
      "Project Project15 matched to students: []\n",
      "Project Project16 matched to students: []\n",
      "Project Project17 matched to students: []\n",
      "Project Project18 matched to students: []\n",
      "Project Project19 matched to students: [10]\n",
      "Project Project20 matched to students: [11, 14]\n",
      "Project Project21 matched to students: [7]\n",
      "Project Project22 matched to students: [20]\n",
      "Project Project23 matched to students: []\n",
      "Project Project24 matched to students: []\n",
      "Project Project25 matched to students: []\n",
      "Project Project26 matched to students: []\n",
      "Project Project27 matched to students: []\n",
      "Project Project28 matched to students: []\n"
     ]
    }
   ],
   "source": [
    "# Run the algorithm\n",
    "# By default, we will consider all given preferences\n",
    "N_PREFERENCES_TO_CONSIDER = student_preferences.shape[1] - 1\n",
    "\n",
    "gale_shapley(students, projects, N_PREFERENCES_TO_CONSIDER)\n",
    "\n",
    "# Print the results\n",
    "print(\"==========\")\n",
    "print(\"Student Assignments:\")\n",
    "for student in students:\n",
    "    print(f\"Student {student.id} matched to Project {student.matched_project.id if student.matched_project is not None else 'None'} with rank choice {student.rank_choice}\")\n",
    "\n",
    "print(\"\\nProject Assignments:\")\n",
    "for project in projects:\n",
    "    print(f\"Project {project.id} matched to students: {[s.id for s in project.matched_students]}\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Matching score: 147.9\n"
     ]
    }
   ],
   "source": [
    "print(f'Matching score: {rate_matching(students)}')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Check validity and export"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Minor Warning - Some students are not matched to any project\n",
      "Matching is valid\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# check validity of matching\n",
    "check_matching(students, projects)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "# save as pandas\n",
    "matching_student_df = pd.DataFrame(columns=[\"student\", \"project\", \"rank_choice\", \"preference\"])\n",
    "for i in range(len(students)):\n",
    "    student = students[i]\n",
    "    if student.matched_project is not None:\n",
    "        matching_student_df.loc[i] = [student.id, student.matched_project.id, student.rank_choice, student.preferences]\n",
    "    else: \n",
    "        matching_student_df.loc[i] = [student.id, None, 0, student.preferences]\n",
    "\n",
    "matching_project_df = pd.DataFrame(columns=[\"project\", \"students\", \"capacity\"])\n",
    "for i in range(len(projects)):\n",
    "    project = projects[i]\n",
    "    matching_project_df.loc[i] = [project.id, [s.id for s in project.matched_students], project.capacity]\n",
    "\n",
    "# join project_capacities\n",
    "matching_project_df = matching_project_df.merge(project_capacities[[\"project\",\"supervisor\"]], left_on=\"project\", right_on=\"project\", how=\"left\")\n",
    "\n",
    "# # export to csv\n",
    "matching_student_df.to_csv(\"matching_student.csv\", index=False)\n",
    "matching_project_df.to_csv(\"matching_project.csv\", index=False)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Evaluation of allocations"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>student</th>\n",
       "      <th>project</th>\n",
       "      <th>rank_choice</th>\n",
       "      <th>preference</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>Project1</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project1, Project20, Project3, Project21, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>2</td>\n",
       "      <td>Project10</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project10, Project1, Project4, Project3, Proj...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>3</td>\n",
       "      <td>Project4</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project4, Project3, Project19, Project21, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>4</td>\n",
       "      <td>Project12</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project12, Project21, Project13, Project20, P...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>5</td>\n",
       "      <td>Project11</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project11, Project1, Project14, Project1, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>6</td>\n",
       "      <td>Project3</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project3, Project22, Project13, Project3, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>7</td>\n",
       "      <td>Project21</td>\n",
       "      <td>2</td>\n",
       "      <td>[Project12, Project21, Project4, Project21, Pr...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>8</td>\n",
       "      <td>Project14</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project14, Project17, Project2, Project1, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>9</td>\n",
       "      <td>Project6</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project6, Project8, Project10, Project22, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>10</td>\n",
       "      <td>Project19</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project19, Project20, Project1, Project21, Pr...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10</th>\n",
       "      <td>11</td>\n",
       "      <td>Project20</td>\n",
       "      <td>2</td>\n",
       "      <td>[Project1, Project20, Project3, Project21, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>12</td>\n",
       "      <td>Project5</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project5, Project12, Project21, Project13, Pr...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>12</th>\n",
       "      <td>13</td>\n",
       "      <td>Project5</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project5, Project11, Project1, Project14, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>14</td>\n",
       "      <td>Project20</td>\n",
       "      <td>5</td>\n",
       "      <td>[Project4, Project3, Project22, Project13, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>14</th>\n",
       "      <td>15</td>\n",
       "      <td>Project7</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project7, Project12, Project21, Project4, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>16</td>\n",
       "      <td>None</td>\n",
       "      <td>0</td>\n",
       "      <td>[Project14, Project1, Project4, Project13, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>16</th>\n",
       "      <td>17</td>\n",
       "      <td>Project13</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project13, Project3, Project12, Project5, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>18</td>\n",
       "      <td>None</td>\n",
       "      <td>0</td>\n",
       "      <td>[Project4, Project21, Project11, Project5, Pro...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>18</th>\n",
       "      <td>19</td>\n",
       "      <td>Project2</td>\n",
       "      <td>1</td>\n",
       "      <td>[Project2, Project1, Project10, Project4, Proj...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>20</td>\n",
       "      <td>Project22</td>\n",
       "      <td>2</td>\n",
       "      <td>[Project10, Project22, Project4, Project7, Pro...</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "    student    project  rank_choice  \\\n",
       "0         1   Project1            1   \n",
       "1         2  Project10            1   \n",
       "2         3   Project4            1   \n",
       "3         4  Project12            1   \n",
       "4         5  Project11            1   \n",
       "5         6   Project3            1   \n",
       "6         7  Project21            2   \n",
       "7         8  Project14            1   \n",
       "8         9   Project6            1   \n",
       "9        10  Project19            1   \n",
       "10       11  Project20            2   \n",
       "11       12   Project5            1   \n",
       "12       13   Project5            1   \n",
       "13       14  Project20            5   \n",
       "14       15   Project7            1   \n",
       "15       16       None            0   \n",
       "16       17  Project13            1   \n",
       "17       18       None            0   \n",
       "18       19   Project2            1   \n",
       "19       20  Project22            2   \n",
       "\n",
       "                                           preference  \n",
       "0   [Project1, Project20, Project3, Project21, Pro...  \n",
       "1   [Project10, Project1, Project4, Project3, Proj...  \n",
       "2   [Project4, Project3, Project19, Project21, Pro...  \n",
       "3   [Project12, Project21, Project13, Project20, P...  \n",
       "4   [Project11, Project1, Project14, Project1, Pro...  \n",
       "5   [Project3, Project22, Project13, Project3, Pro...  \n",
       "6   [Project12, Project21, Project4, Project21, Pr...  \n",
       "7   [Project14, Project17, Project2, Project1, Pro...  \n",
       "8   [Project6, Project8, Project10, Project22, Pro...  \n",
       "9   [Project19, Project20, Project1, Project21, Pr...  \n",
       "10  [Project1, Project20, Project3, Project21, Pro...  \n",
       "11  [Project5, Project12, Project21, Project13, Pr...  \n",
       "12  [Project5, Project11, Project1, Project14, Pro...  \n",
       "13  [Project4, Project3, Project22, Project13, Pro...  \n",
       "14  [Project7, Project12, Project21, Project4, Pro...  \n",
       "15  [Project14, Project1, Project4, Project13, Pro...  \n",
       "16  [Project13, Project3, Project12, Project5, Pro...  \n",
       "17  [Project4, Project21, Project11, Project5, Pro...  \n",
       "18  [Project2, Project1, Project10, Project4, Proj...  \n",
       "19  [Project10, Project22, Project4, Project7, Pro...  "
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "matching_student_df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Total matched students: 18'"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# total matched students\n",
    "f'Total matched students: {len(matching_student_df[~matching_student_df[\"project\"].isnull()])}'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Students without projects: 2'"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "f'Students without projects: {len(matching_student_df[matching_student_df[\"project\"].isnull()])}'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'Unmatched projects: 11'"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "f'Unmatched projects: {len(matching_project_df[(matching_project_df[\"students\"].apply(len) == 0) & (matching_project_df[\"capacity\"]>0)])}'"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "rank_choice\n",
       "0     2\n",
       "1    14\n",
       "2     3\n",
       "5     1\n",
       "Name: student, dtype: int64"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "matching_student_df.groupby('rank_choice').student.count()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>project</th>\n",
       "      <th>students</th>\n",
       "      <th>capacity</th>\n",
       "      <th>supervisor</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>Project8</td>\n",
       "      <td>[]</td>\n",
       "      <td>3</td>\n",
       "      <td>B</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>Project9</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>C</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>14</th>\n",
       "      <td>Project15</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>D</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>Project16</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>D</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>16</th>\n",
       "      <td>Project17</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>E</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>Project18</td>\n",
       "      <td>[]</td>\n",
       "      <td>3</td>\n",
       "      <td>E</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>22</th>\n",
       "      <td>Project23</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>G</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>23</th>\n",
       "      <td>Project24</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>G</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>24</th>\n",
       "      <td>Project25</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>G</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>26</th>\n",
       "      <td>Project27</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>H</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>27</th>\n",
       "      <td>Project28</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>H</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "      project students  capacity supervisor\n",
       "7    Project8       []         3          B\n",
       "8    Project9       []         1          C\n",
       "14  Project15       []         1          D\n",
       "15  Project16       []         1          D\n",
       "16  Project17       []         1          E\n",
       "17  Project18       []         3          E\n",
       "22  Project23       []         1          G\n",
       "23  Project24       []         1          G\n",
       "24  Project25       []         1          G\n",
       "26  Project27       []         1          H\n",
       "27  Project28       []         1          H"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# empty projects\n",
    "matching_project_df[(matching_project_df[\"students\"].apply(len) == 0) & (matching_project_df[\"capacity\"]>0)]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>project</th>\n",
       "      <th>students</th>\n",
       "      <th>capacity</th>\n",
       "      <th>supervisor</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>Project7</td>\n",
       "      <td>[15]</td>\n",
       "      <td>2</td>\n",
       "      <td>B</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>Project8</td>\n",
       "      <td>[]</td>\n",
       "      <td>3</td>\n",
       "      <td>B</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>Project9</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>C</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>14</th>\n",
       "      <td>Project15</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>D</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>Project16</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>D</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>16</th>\n",
       "      <td>Project17</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>E</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>Project18</td>\n",
       "      <td>[]</td>\n",
       "      <td>3</td>\n",
       "      <td>E</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>22</th>\n",
       "      <td>Project23</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>G</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>23</th>\n",
       "      <td>Project24</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>G</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>24</th>\n",
       "      <td>Project25</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>G</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>26</th>\n",
       "      <td>Project27</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>H</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>27</th>\n",
       "      <td>Project28</td>\n",
       "      <td>[]</td>\n",
       "      <td>1</td>\n",
       "      <td>H</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "      project students  capacity supervisor\n",
       "6    Project7     [15]         2          B\n",
       "7    Project8       []         3          B\n",
       "8    Project9       []         1          C\n",
       "14  Project15       []         1          D\n",
       "15  Project16       []         1          D\n",
       "16  Project17       []         1          E\n",
       "17  Project18       []         3          E\n",
       "22  Project23       []         1          G\n",
       "23  Project24       []         1          G\n",
       "24  Project25       []         1          G\n",
       "26  Project27       []         1          H\n",
       "27  Project28       []         1          H"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# projects with remaining capacity\n",
    "matching_project_df[(matching_project_df[\"capacity\"] - matching_project_df[\"students\"].apply(len)) > 0]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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