ImportError: cannot import name 'send_file' from 'flask'

ImportError: cannot import name ‘send_file’ from ‘flask’

$ python -c "from flask import send_file"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: cannot import name 'send_file' from 'flask' (unknown location)

Why this happens

The usual suspects apply: local shadowing (a flask.py file or flask/ directory in your project), installing Flask in a different interpreter than you’re using, or creating circular imports that cause partially-initialized modules. Since send_file is a top-level Flask import, these issues often manifest early.

Fix

• Ensure no local files or folders are named flask.
• Verify the active environment: python -m pip show flask and align your interpreter.
• Import send_file only in your route modules; avoid importing the app within those modules.

Wrong code

# files.py
from app import app
from flask import send_file

@app.route('/download')
def download():
    return send_file('data.csv')

Fixed code

# files.py
from flask import send_file

def register(app):
    @app.route('/download')
    def download():
        return send_file('data.csv')

# app/__init__.py
from flask import Flask
from .files import register
app = Flask(__name__)
register(app)

Keep imports simple, avoid cycles, and confirm your environment to prevent ImportError.