A modular pattern for injecting your own template utils (i.e. functions) into Flask's template contexts

app.py

from flask import Flask

app = Flask(__name__)

# Register core.utils with all template contexts
import utils
@app.context_processor
def utils_context():
    return utils.registry

template.html

{{ foo() }}
{{ bar() }}

utils.py

"""
Define your utils here. Decorate anything you want made available to your templates with @util
"""

registry = {}

def util(func):
    registry[func.__name__] = func
    return func

@util
def foo():
    return "foo"

@util
def bar():
    return "bar"