Versioning with flask blueprint

versioning.py

from flask import Blueprint
from flask import Flask

app = Flask(__name__)


v1 = Blueprint("version1", "version1")
v2 = Blueprint('version2', "version2")


@v2.route("/foo")
def index():
    return "v2 foo looks different than v1"

@v1.route("/foo")
def index():
    return "v1 foo looks different than v2"


@v2.route("/bar")
@v1.route("/bar")
def hello():
    return "bar stays the same for v1 and v2"


@app.route('/get_rules')
def root():
    rules = [str(rule) for rule in app.url_map.iter_rules()]
    return "\n".join(rules)


app.register_blueprint(v1, url_prefix="/v1")
app.register_blueprint(v2, url_prefix="/v2")
app.register_blueprint(v2, url_prefix="/")
app.run(port=8080)

This snippet showcases the following:

• multiple versions in the same code
• version prefixes via Blueprints
• routes can use the same code (/v1/bar and /v2/bar)
• the latest version is also the "root" version ( /bar is equal to /v2/bar

There are some pitfalls here:

• app.register() calls must be below the route definitions
• url_prefix has no default to /, so app.register_blueprint(v2) simply does nothing