Python API wrapper for the Yahoo Fantasy Sports public API

Author: Wren J. R. (uberfastman)

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READ THE DOCS HERE!
^{Detailed documentation on YFPY can be found at https://yfpy.uberfastman.com.}

• About
• Installation
  • Pip
  • Manual
• Setup
  • Yahoo Developer Network App
  • Environment Variables
• Usage
  • Authentication
    • Programmatic Persistent Authentication
    • Persistent Authentication Using Access Token Fields
    • Persistent Authentication Using Access Token JSON
  • Querying the Yahoo Fantasy Sports API
  • Docker
    • Docker Development
    • Docker Image Deployment
• Testing
  • Unit Tests
  • Integration Tests
  • Run Tests
• Dependencies
  • Platform
  • Python
  • Development
• Troubleshooting
  • Yahoo Fantasy Sports API

YFPY is a comprehensive wrapper around the Yahoo Fantasy Sports API. It allows for easy retrieval and parsing of almost any data you might wish to extract and use from any Yahoo fantasy league to which your Yahoo account has access (or for public leagues). The primary focus of this wrapper is on fantasy football (NFL), but it also supports usage with fantasy hockey (NHL), fantasy baseball (MLB), and fantasy basketball (NBA).

• If you wish to use YFPY within another project, from within your project directory, run

  pip install yfpy

  or add yfpy to your project requirements.txt.

• If you wish to download and use YFPY locally, clone the git repository:

  git clone git@github.com:uberfastman/yfpy.git

In order to use YFPY with private fantasy leagues, you must set up an app on your Yahoo account to allow access. Follow the step-by-step guide below for instructions on how to do so, or see Getting Started in the Yahoo Developer Network docs for more details.

Note: If you are only planning on using YFPY to pull "read only" data from public leagues, you do not need to do this.

• Log in to a Yahoo account with access to whatever fantasy leagues from which you wish to retrieve data.
• Go to https://developer.yahoo.com/apps/create/ and create an app (you must be logged into your Yahoo account as stated above). For the app, select the following options:
  • Application Name (Required): yfpy (you can name your app whatever you want, but this is just an example).
  • Application Type (Required): select the Installed Application radio button.
  • Description (Optional): you may write a short description of what the app does.
  • Home Page URL (Optional): if you have a web address related to your app you may add it here.
  • Redirect URI(s) (Required): this field must contain a valid redirect address, so you can use https://localhost:8080
  • API Permissions (Required): check the Fantasy Sports checkbox. You can leave the Read option selected (appears in an accordion expansion underneath the Fantasy Sports checkbox once you select it).
  • Click the Create App button.
  • Once the app is created, it should redirect you to a page for your app, which will show both a Client ID and a Client Secret.
  • Copy the Client ID and Client Secret and proceed with the steps in Environment Variables or Programmatic Persistent Authentication.

YFPY now supports the usage of environment variables, either directly within the command line or using a .env file. Any environment variables exported to the same shell in which YFPY runs will automatically be read when a YahooFantasySportsQuery object is instantiated when env_var_fallback=True (default).

• If you wish to also use environment variables stored in a .env file, you can set up a .env file by making a copy of .env.template in the root project directory and renaming it .env (you can do this in the command line by running cp .env.template .env).
• Paste the Client ID and Client Secret retrieved by following the steps in Yahoo Developer Network App into their respective environment variables in your .env file:

YAHOO_CONSUMER_KEY=<YAHOO_DEVELOPER_APP_CONSUMER_KEY_STRING>
YAHOO_CONSUMER_SECRET=<YAHOO_DEVELOPER_APP_CONSUMER_SECRET_STRING>

• YFPY is configured by default to check for environment variables for authentication with Yahoo, so you will now be able to proceed directly to Authentication.

Note: You can disable the fallback to environment variables behavior during instantiation of a YFPY query by passing the argument env_var_fallback=False to the object:

from yfpy.query import YahooFantasySportsQuery

query = YahooFantasySportsQuery(
    league_id="<YAHOO_LEAGUE_ID>",
    game_code="nfl",
    game_id=449,
    yahoo_consumer_key="<YAHOO_CONSUMER_KEY>",
    yahoo_consumer_secret="<YAHOO_CONSUMER_SECRET>",
    env_var_fallback=False
)

• Follow the instructions in the Installation and Setup sections.
• The first time you use YFPY, a browser window will open up asking you to allow your app to access your Yahoo fantasy sports data. You MUST hit allow, and then copy the verification code that pops up into the command line prompt where it will now be asking for verification, hit enter, and the OAuth2 three-legged handshake should be complete and your data should have been successfully retrieved.

Note: If you are running YFPY in Docker, instead of opening a new browser window, YFPY will output a URL to the command line, which you must then copy to a browser window in order to log in to your Yahoo account, allow access to your app, and retrieve the required verification code.

YFPY supports programmatic authentication using yahoo_consumer_key and yahoo_consumer_secret arguments when instantiating a YahooFantasySportsQuery object. Additionally, you can pass in either a valid JSON string or a Python dictionary to yahoo_access_token_json containing all required fields of a Yahoo access token.

• Providing yahoo_consumer_key and yahoo_consumer_secret overrides any values provided in a .env file.
• Providing a value to yahoo_access_token_json overrides yahoo_consumer_key/yahoo_consumer_secret values and any values provided in a .env file for Yahoo access token individual fields.
  • Required fields (either in a JSON string with escaped double quotes or a Python dictionary) for the value of yahoo_access_token_json are the following:
    • access_token
    • consumer_key
    • consumer_secret
    • guid
    • refresh_token
    • token_time
    • token_type
  • The consumer_key and consumer_secret fields in yahoo_access_token_json override any values provided in yahoo_consumer_key/yahoo_consumer_secret.

Example of Using yahoo_access_token_json:

from yfpy.query import YahooFantasySportsQuery

query = YahooFantasySportsQuery(
    league_id="<YAHOO_LEAGUE_ID>",
    game_code="nfl",
    game_id=449,
    yahoo_access_token_json={
        "access_token": "<YAHOO_ACCESS_TOKEN>",
        "consumer_key": "<YAHOO_CONSUMER_KEY>",
        "consumer_secret": "<YAHOO_CONSUMER_SECRET>",
        "guid": "<YAHOO_TOKEN_GUID>",
        "refresh_token": "<YAHOO_REFRESH_TOKEN>",
        "token_time": 1234567890.123456,
        "token_type": "bearer"
    }
)

• YFPY no longer uses JSON files to store Yahoo credentials or access tokens. However, if you wish to preserve your access token in order to remain verified, you can now instantiate a YFPY query with save_token_data_to_env_file=True, which will write all required Yahoo access token fields an .env file located in the provided env_file_location directory.
• For all subsequent runs of your app, you should be able to keep retrieving Yahoo fantasy sports data using YFPY without re-verifying, since the generated refresh token should now just renew whenever you use the same .env file to authenticate your app.

Note: You MUST provide a value for env_file_location or else NO Yahoo access token data will be saved!

• YFPY also supports the use of a single environment variable by providing a valid JSON string in YAHOO_ACCESS_TOKEN_JSON. This environment variable is only used if env_var_fallback=True (default) when instantiating a YFPY query.

• See the documentation on the yfpy.query.YahooFantasySportsQuery class for example usage of all available queries.
• See quickstart/quickstart.py for example usage output.
  • Uncomment/comment out whichever configuration values in their respective functions with which you wish to experiment.
  • Uncomment/comment out whichever query lines in the RUN QUERIES section you wish to run.
  • Uncomment/comment out whichever query lines in the CHECK FOR MISSING DATA FIELDS section you wish to check for any new/missing data fields returned by the Yahoo Sports Fantasy Football API.

YFPY can be used within Docker for a more seamless, platform-agnostic experience.

• Run the Docker container (pulls the YFPY Docker image from GitHub Package Registry):

  docker compose up

• You can then run commands in the Docker container in two different ways:
  • Connect to the running container and run commands from within it:

    docker exec -it yfpy-package-1 bash

    Then:

    python quickstart/quickstart.py

  • Send commands to the running container from your host machine:

    docker exec -i yfpy-package-1 bash -c "python quickstart/quickstart.py"

• Run the Docker container for local development (mount all local code into container):

  docker compose -f compose.yaml -f compose.dev.yaml up

See DEPLOYMENT.md for Docker image deployment.

YFPY has a collection of fully functional code snippets that can be run using pytest. These snippets demonstrate how to use YFPY to retrieve your Yahoo Fantasy Sports data.

• See the test/unit directory for example code snippets using pytest.

• See the test/integration directory for example code snippets using pytest.
• Before running any integration tests, make a copy of auth/.env.template in the auth/ directory and rename it to .env.
• Copy your Yahoo Client ID and Client Secret into the environment variables in .env so that pytest can use them when hitting the Yahoo Fantasy Sports API.
• If this is the first time running pytest with your Yahoo API credentials, you MUST allow interactive prompts within pytest by using the -s flag.
• The fixture values in test/integration/conftest.py are defined in quickstart/quickstart.py, and can be changed for testing by uncommenting/commenting out the values inside each respective function.

• You can invoke all pytest tests (both integration test and unit tests) by running the below from the root directory:
  • pytest -v -s
• If you want to run only the unit tests, you can run:
  • pytest -v -s -m unit
• If you want to run only the integration tests, you can run:
  • pytest -v -s -m integration

YFPY has only been tested extensively on macOS, but is written to be platform-agnostic, and seems to work without issue on Windows and Linux.

YFPY requires Python 3.10 or later, and has been tested through Python 3.12.

Direct project dependencies can be viewed in requirements.txt, and additional development and build dependencies (not including transitive dependencies) can be viewed in requirements-dev.txt.

Occasionally when you use the Yahoo Fantasy Sports API, there are hangups on the other end that can cause data not to transmit, and you might encounter an error similar to this:

Traceback (most recent call last):
  File "yfpy-app.py", line 114, in <module>
    var = app.run()
  File "/Users/your_username/PATH/T0/LOCAL/PROJECT/yfpy-app.py", line 429, in run
    for team in team_standings:
IndexError: list index out of range

Typically, when the above error (or a similar error) occurs, it simply means that one of the Yahoo Fantasy Sports API calls failed and so no data was retrieved. This can be fixed by simply re-running data query.