The Colorado Board of Elections requested an audit of a recent local congressional election. The Colorado Board of Elections requested to find the following:
- Calculate the total number of votes cast
- Get a complete list of candidates who received votes
- List the counties that received votes
- Calculate the total number of votes each candidate received
- Total number of votes by county
- Calculate the percentage of votes each candidate won
- Determine the county with the largest voter turnout
- Determine the winner of the election based on popular vote
- Data Source: election_results.csv
- Software: Python v3.7.6 and Visual Studio Code v1.51.1
The Python code needed to use for loops and conditional statements with membership and logical operators to find the requested results. It then needed to print the results to the command line and save them to election_analysis.txt.
This Python script required two dependencies: csv and os. These packages allow Python to read CSVs and interact with the operating system.
# Add our dependencies
import csv
import os
# Add a variable to load a file from a path
file_to_load = os.path.join(".", "Resources", "election_results.csv")
# Add a variable to save the file to a path
file_to_save = os.path.join("analysis", "election_analysis.txt")This code snippet will initialize variables, lists, and dictionaries for candidates and counties.
total_votes = 0
candidate_options = []
candidate_votes = {}
county = []
county_votes = {}
winning_candidate = ""
winning_count = 0
winning_percentage = 0Python will then track the largest county and county voter turnout. It will read a CSV, convert it into a list of dictionaries, and tally the total vote and get candidate names using a for-loop.
largest_turnout = ""
winning_turnout = 0
with open(file_to_load) as election_data:
reader = csv.reader(election_data)
header = next(reader)
for row in reader:
total_votes = total_votes + 1
candidate_name = row[2]Here, the county name's are extracted from each row of the CSV. An if-statement is used to find unique candidate names, add them to the list, and then begin tracking the candidate's vote count.
county_name = row[1]
if candidate_name not in candidate_options:
candidate_options.append(candidate_name)
candidate_votes[candidate_name] = 0
candidate_votes[candidate_name] += 1 Another if-statement is used that checks if the county is already in the list. If it is not, it is added to the list and then begins tracking the county's vote count.
if county_name not in county:
county.append(county_name)
county_votes[county_name] = 0 This code snippet will add a vote to that county's vote count.
county_votes[county_name] += 1Python will save the results of the counts to election_analysis.txt and also print them to the terminal.
with open(file_to_save, "w") as txt_file:
election_results = (
f"\nElection Results\n"
f"-------------------------\n"
f"Total Votes: {total_votes:,}\n"
f"-------------------------\n\n"
f"County Votes:\n"
)
print(election_results, end="")
txt_file.write(election_results)A for-loop is used to get the county from the county dictionary, calculate percentage of votes for the county, print them to the terminal, and also write the county votes to election_analysis.txt. An if-statement is used to determine the winning county and get its vote count.
for county_name in county:
turnout = county_votes[county_name]
turnout_percentage = float(turnout) / float(total_votes) * 100
county_results = (f'{county_name}: {turnout_percentage:.1f}% ({turnout:,})\n')
print(county_results)
txt_file.write(county_results)
if (turnout > winning_turnout):
winning_turnout = turnout
largest_turnout = county_namef-strings are used to print out the county with the largest turnout to the terminal.
largest_turnout_summary = (
f"--------------------------\n"
f"Largest Turnout: {largest_turnout}\n"
f"--------------------------\n"
)
print(largest_turnout_summary)
This part of the code saves the county with the largest voter turnout, final candidate vote count, and percentage to election_analysis.txt. These values are also printed to the terminal.
```python
txt_file.write(largest_turnout_summary)
for candidate_name in candidate_votes:
votes = candidate_votes.get(candidate_name)
vote_percentage = float(votes) / float(total_votes) * 100
candidate_results = (
f"{candidate_name}: {vote_percentage:.1f}% ({votes:,})\n")
print(candidate_results)
txt_file.write(candidate_results)
if (votes > winning_count) and (vote_percentage > winning_percentage):
winning_count = votes
winning_candidate = candidate_name
winning_percentage = vote_percentage
winning_candidate_summary = (
f"-------------------------\n"
f"Winner: {winning_candidate}\n"
f"Winning Vote Count: {winning_count:,}\n"
f"Winning Percentage: {winning_percentage:.1f}%\n"
f"-------------------------\n"
)
print(winning_candidate_summary)
txt_file.write(winning_candidate_summary)- Total Votes: 369,711
- County Votes:
- Jefferson: 10.5% (38,855)
- Denver: 82.8% (306,055)
- Arapahoe: 6.7% (24,801)
- Largest Turnout: Denver
- Vote Total By Candidate:
- Charles Casper Stockham: 23.0% (85,213)
- Diana DeGette: 73.8% (272,892)
- Raymon Anthony Doane: 3.1% (11,606)
- Winner: Diana DeGette
- Winning Vote Count: 272,892
- Winning Percentage: 73.8%
It is recommended that the Colorado Board of Elections maintain this script for future use so that it can be refactored for future elections, which could have different candidates or different counties. It should be noted that this script will only execute against a CSV and not an Excel spreadsheet (.xlsx).
This script is written to execute against this particular CSV, so if candidate names and county names are in a different column, lines 56 and 59 in PyPoll_Challenge.py will need to be modified:
# Get the candidate name from each row
candidate_name = row[2]
# 3: Extract the county name from each row
county_name = row[1]This script is written to output the winning candidate, winning vote count, and winning percentage. If the Colorado Board of Elections wants to show the losing candidate, losing vote count, and losing percentage, the lines of code shown below will need to be modified.
# Determine winning vote count, winning percentage, and candidate
if (votes > winning_count) and (vote_percentage > winning_percentage):
winning_count = votes
winning_candidate = candidate_name
winning_percentage = vote_percentage
# Print the winning candidate (to terminal)
winning_candidate_summary = (
f"-------------------------\n"
f"Winner: {winning_candidate}\n"
f"Winning Vote Count: {winning_count:,}\n"
f"Winning Percentage: {winning_percentage:.1f}%\n"
f"-------------------------\n"
)
print(winning_candidate_summary)