How do you apply two methods to a function in Python?

I am running this code to create a SHA1 Hash.

import hashlib
import os

"""
   Program to Hash a file, works in Python 2
"""

def sha1sum(filename):
    hash = hashlib.sha1(filename.read())
    return hash.hexdigest()

with open('f1.py') as filename:
    mysum = sha1sum(filename)

print(mysum)

This works in Python 2 but in Python 3 I need to "encode" the data and get the following error message

TypeError: Unicode-objects must be encoded before hashing

A little Googling tells me I need to .encode. Something like this

filename.encoding('utf-8')

From what I can tell this means I need to apply two methods to filename argument

filename.read() and filename.encode('utf-8')

Is this assumption correct?

If so I tried changing

hash = hashlib.sha1(filename.read())

To

hash = hashlib.sha1(filename.read())filename.encode('utf-8')))

And I get the following error

hash = hashlib.sha1(filename.read())filename.encode('utf-8') ^ SyntaxError: invalid syntax

I am not sure what the proper syntax would be or how to proceed. Thanks in advance.