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This guide will get you started pulling data from your Yahoo Fantasy Football League

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Please use this data to make some slick visualizations of just how awesome, balanced, or powerful your team and/or league is!

Data pulled from the Yahoo API is in the form of JSON. You can utilize the files in this format if you feel comfortable working with it, or you can utilize the Data Transformation script (Data_Transformations.py) or the Jupyter Notebook to convert some of the data into a more friendly CSV.

Once the data is output in .csv format you can then use those files in Excel, Tableau, or with any visualization package available in Python.

There is a Data Analysis folder with some beginnings of automated charts that can be created in Seaborn. This is obviously much easier and faster in a program like Excel or Tableau, but if you're like me and like clicking one button to extract, parse, compile, sort, and export my data, then this tool was made for you! (Note that data viz is done in Jupyter Notebooks for ease of displaying the graphs inline)

In order for this whole thing to run correctly, you will need to update a few key scripts, data files, and get your Yahoo API authorization tokens (very easy):

It may be easier to install a text editor like Atom to do all of these next steps in one application...that's up to you. You can easily edit JSON files by changing the extension from .json to .txt, make the desired edits, and change the extension back to .json.

Requirements:

• Python 3

• IDE/text editor of your choice

• Jupyter Notebooks (for data visualizations)

• Knowledge/experience running and executing Python (.py) scripts in and IDE or command line

• Yahoo Developer Account (process outlined below)

• Libraries needed

  • pandas (https://pandas.pydata.org/)
  • yahoo_oauth (https://pypi.org/project/yahoo_oauth/)
  • datetime & json (bundled with Python)

  If using the visualizations in ./Data Analysis/

  • Seaborn (https://seaborn.pydata.org/)
  • Numpy (http://www.numpy.org/)
  • Matplotlib (https://matplotlib.org/)

League Details

• This script assumes a 16-week schedule, including playoffs. If your league differs, then you'll need to change the details in the league_info_form.txt file in the Initial_Setup folder.
• In the same vein, this assumes a 12-team league.
• Update your roster position details as well in the league_info_form.txt file. Default is QB,WR1,WR2,WR3,RB1,RB2,TE,W/R/T,K,DEF,BN1-6, however 10 bench spots are shown to account for overflow in either unrostered players, or empty roster positions during the waiver/drop/add period each week. As a rule of thumb, add 4 bench ('BN') to your roster here to account for the unknown
• Add your 'league_id'. This can be found in your league's unique Yahoo Fantasy Football URL: "https://football.fantasysports.yahoo.com/f1/XXXXXX"

Background Information

Yahoo has not updated their API documentation for quite some time. In an effort to try and gather some raw data from my fantasy football league I pieced together 3 different libraries previously used to access the Yahoo API. This was a trial and error method since each library hadn't been updated in a few years, and there were no clear examples of input/output for a fantasy sports application. The login and authentication process used in these scripts should be applicable to every other fantasy sport league hosted on Yahoo, as long as the appropriate Game Key is utilized.

In the code you'll see the following notation used to identify your specific league:

"game_key.l.league_id"

• game_key is the NFL Game Key which Yahoo doesn't publish. The latest update will automatically generate this key for you.
  • If you want to find MLB, NHL, or another game key, you can use the get_league_info.py script to find that specific key. Just specify the sport you are looking for.
• XXXXXX is the league ID, this is published each year on the on your league's unique Yahoo Fantasy Football URL: https://football.fantasysports.yahoo.com/f1/XXXXXX

Process for updating the script with you league information:

1. Update fantasy_stats.py Note: This previously needed to be input manually throughout the main script, this is no longer required. You only need to update your League ID in one location.

• 1.1) League ID is listed in the league_info_form.txt file in the Initial_Setup folder to be filled out.
• 1.2) Game Key will be generated from the be the current Fantasy Football year. It's generated in the UpdateYahooLeagueInfo() function.

  • Game Keys for previous years can be manually overwritten by replacing the 'game_key' variable with the specific year you want to see. Note, you will also need the previous years' league_id as well. You can use the following URL to access specific seasons, or multiple: url = 'https://fantasysports.yahooapis.com/fantasy/v2/games;game_codes=nfl;seasons=2020,2021' For quick reference, the Game Key for the NFL for the last few seasons are:

    Year	Game Key
    2015	348
    2016	359
    2017	371
    2018	380
    2019	390
    2020	399
    2021	406
    2022	414

2. Update /teams/team_numbers.txx, team_mapping_full.txt, and team_mapping_initials.txt

• 2.1) For first time users, update the manager's nickname/real name for each team. Go to https://football.fantasysports.yahoo.com/f1/XXXXXX/1 to find out which manager is considered Team 1 in your league (i.e. replace 'Manager 1 Name' with 'Steve'). Repeat for each team. Record each manager's name in this .txt file accordingly. Add or delete any extra teams as needed, as this script was originally written for a 12-team league. Just be sure to use the correct formatting (comma at end of line, except for the last line). This file is currently used as reference, and not actually used in the script, but it may in the future. Use for your reference.
• 2.2) For team_mapping files, do the same as above, just with the actual Yahoo manager names. For example, if a managers name is Dwayne "The Rock" Johnson, he may put his initial, "DTRJ", as his name in his Yahoo account. You'll want to fill out the team_mapping file as, "DTRJ":"The Rock", OR "DTRJ":"Dwayne", whatever you want the display name to be in all your data files. If there's two managers with the same name, you may want to differentiate them. You can find the Yahoo name listed in each players profile. Full names are used in the Data Transformations script, and the Initials are used in the visualization script for more visually appealing labels.

3. Register for Yahoo Developer Network and get your credentials:

• 3.1) Register for a Yahoo account at https://yahoo.com/
• 3.2) Go to https://developer.yahoo.com/ --> 'My Apps' --> 'YDN Apps'
• 3.3) On the lefthand panel, click 'Create an App'
• 3.4) Name your app whatever you please ("Fantasy Football Stats") in the 'Application Name' block.
• 3.5) Select the 'Installed Application' option since we're only going to be accessing the data from our local machines.
• 3.6) Under the 'API Permissions' sections select 'Fantasy Sports' and then make sure that 'Read' is selected. 'Read/Write' would only be used if you wanted to be able to control your league via Python scripting vice just reading the data from your league. You can come back and change these options in the future.
• 3.7) You have now successfully created a Yahoo Developer App and you will see App ID, Client ID(Consumer Key), and Client Secret(Consumer Secret) with a long string of random letters and numbers. Yahoo will use these keys to allow you to access it's API via OAuth 2.0.

4. Update the Yahoo OAuth files

• 4.1) In the folder ./auth/, open oauth2yahoo.json to edit.
• 4.2) Copy both your Consumer Key and Consumer Secret Key into the respective lines. After you allow access (next step), you will see 'Access Key', 'Refresh Token', 'Token Time', and 'Token Type' automatically be added to this file. DO NOT EDIT THIS FILE EVER AGAIN OR YOU WILL BE IN A WORLD OF HURT
• 4.3) Run the league_authorization.py script in the Initial_Setup folder first in order to authorize your app. This only uses the Consumer Key and Consumer Secret Key where as all the other scripts utilize the Access Key in addition. You WILL get an error if you run anything else before this script. There is also a jupyter notebbok for those who want to use that instead.
• 4.4) You should now be able to run the main script, fantasy_stats.py
• 4.5) You can disable this scripts access to your league by going to your Yahoo Account Info --> Recent Activity --> Apps Connected to Your Account --> 'remove' access to your created app

5. Update Data_Transformations.py under the Data Analysis Folder

• 5.1) Update your League ID and Game Key (1 instance)

6. Have fun exploring the data!

• 6.1) Run fantasy_stats.py each week to update all data. Out-weeks will either display 0's for everything or the exact same data as the most current week.

Resources and documentation for future development and data that can be extracted from the Yahoo API:

https://developer.yahoo.com/fantasysports/guide/

https://developer.yahoo.com/fantasysports/guide/game-resource.html#game-resource-desc

https://developer.yahoo.com/apps/