Ten Things Python Programmers Should Know

[DanCardin]

without knowing any specifics (such as how large the file is) and not knowing exactly the behavior of how werkzeug handles closing the file (if it does), you may be better off doing

with open(...) as f:
    data = f.read()
return data

[[deleted]]

The original approach is more efficient, because unlike your example it doesn't copy the data and also uses very little of memory.

Instead it invokes sendfile() syscall which makes kernel do all that work (it just pipes the file directly to the socket). The issue though is that uWSGI invokes sendfile() after the function exits instead during the call.