This answer taught me that you can set headers for an entire session:

s = requests.Session()
s.auth = ('user', 'pass')
s.headers.update({'x-test': 'true'})

# Both 'x-test' and 'x-test2' are sent
s.get('http://httpbin.org/headers', headers={'x-test2': 'true'})

Bonus: Sessions also handle cookies

I strongly favour minimal file headers, by which I mean just:

#!/usr/bin/env python # [1]
"""\
This script foos the given bars [2]

Usage: myscript.py BAR1 BAR2
"""
import os   # standard library, [3]
import sys

import requests  # 3rd party packages

import mypackage  # local source

• [1] The hashbang if, and only if, this file should be able to be directly executed, i.e. run as myscript.py or myscript or maybe even python myscript.py. (The hashbang isn't used in the last case, but providing it gives users the choice of executing it either way.) The hashbang should not be included if the file is a module, intended just to be imported by other Python files.
• [2] Module docstring
• [3] Imports, grouped in the standard way, ie. three groups of imports, with a single blank line between them. Within each group, imports are sorted. The final group, imports from local source, can either be absolute imports as shown, or explicit relative imports.

Everything else is a waste of time - both for the author and for subsequent maintainers. It wastes the precious visual space at the top of the file with information that is better tracked elsewhere, and is easy to get out of date and become actively misleading.

If you have legal disclaimers or licensing info, it goes into a separate file. It does not need to infect every source code file. Your copyright should be part of this. People should be able to find it in your LICENSE file, not random source code.

Metadata such as authorship and dates is already maintained by your source control. There is no need to add a less-detailed, erroneous, and out-of-date version of the same info in the file itself.

I don't believe there is any other data that everyone needs to put into all their source files. You may have some particular requirement to do so, but such things apply, by definition, only to you. They have no place in “general headers recommended for everyone”.

My Opinion

I use this this format, as I am learning, "This is more for my own sanity, than a necessity."

As I like consistency. So, I start my files like so.

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# =============================================================================
# Created By  : Jeromie Kirchoff
# Created Date: Mon August 18 18:54:00 PDT 2018
# =============================================================================
"""The Module Has Been Build for..."""
# =============================================================================
# Imports
# =============================================================================
from ... import ...
<more code...>

1. First line is the Shebang
2. And I know There's no reason for most Python files to have a shebang line but, for me I feel it lets the user know that I wrote this explicitly for python3. As on my mac I have both python2 & python3.
3. Line 2 is the encoding, again just for clarification
4. As some of us forget when we are dealing with multiple sources (API's, Databases, Emails etc.)
5. Line 3 is more of my own visual representation of the max 80 char.
6. I know "Oh, gawd why?!?" again this allows me to keep my code within 80 chars for visual representation & readability.
7. Line 4 & 5 is just my own way of keeping track as when working in a big group keeping who wrote it on hand is helpful and saves a bit of time looking thru your GitHub. Not relevant again just things I picked up for my sanity.
8. Line 7 is your Docstring that is required at the top of each python file per Flake8.

Again, this is just my preference. In a working environment you have to win everyone over to change the defacto behaviour. I could go on and on about this but we all know about it, at least in the workplace.

Header Block

• What is a header block?
• Is it just comments at the top of your code or is it be something which prints when the program runs?
• Or something else?

So in this context of a university setting:

Header block or comments

Header comments appear at the top of a file. These lines typically include the filename, author, date, version number, and a description of what the file is for and what it contains. For class assignments, headers should also include such things as course name, number, section, instructor, and assignment number.

• Is it just comments at the top of your code or is it be something which prints when the program runs? Or something else?

Well, this can be interpreted differently by your professor, showcase it and ask!

"If you never ask, The answer is ALWAYS No."

ie:

# Course: CS108
# Laboratory: A13
# Date: 2018/08/18
# Username: JayRizzo
# Name: Jeromie Kirchoff
# Description: My First Project Program.

If you are looking for Overkill:

or the python way using "Module Level Dunder Names"

Standard Module Level Dunder Names

__author__ = 'Jeromie Kirchoff'
__copyright__ = 'Copyright 2018, Your Project'
__credits__ = ['Jeromie Kirchoff', 'Victoria Mackie']
__license__ = 'MSU'  # Makin' Shi* Up!
__version__ = '1.0.1'
__maintainer__ = 'Jeromie Kirchoff'
__email__ = '[email protected]'
__status__ = 'Prototype'

Add Your Own Custom Names:

__course__ = 'cs108'
__teammates__ = ['Jeromie Kirchoff']
__laboratory__ = 'A13'
__date__ = '2018/08/18'
__username__ = 'JayRizzo'
__description__ = 'My First Project Program.'

Then just add a little code to print if the instructor would like.

print('# ' + '=' * 78)
print('Author: ' + __author__)
print('Teammates: ' + ', '.join(__teammates__))
print('Copyright: ' + __copyright__)
print('Credits: ' + ', '.join(__credits__))
print('License: ' + __license__)
print('Version: ' + __version__)
print('Maintainer: ' + __maintainer__)
print('Email: ' + __email__)
print('Status: ' + __status__)
print('Course: ' + __course__)
print('Laboratory: ' + __laboratory__)
print('Date: ' + __date__)
print('Username: ' + __username__)
print('Description: ' + __description__)
print('# ' + '=' * 78)

End RESULT

Every time the program gets called it will show the list.

$ python3 custom_header.py
# ==============================================================================
Author: Jeromie Kirchoff
Teammates: Jeromie Kirchoff
Copyright: Copyright 2018, Your Project
Credits: Jeromie Kirchoff, Victoria Mackie
License: MSU
Version: 1.0.1
Maintainer: Jeromie Kirchoff
Email: [email protected]
Status: Prototype
Course: CS108
Laboratory: A13
Date: 2018/08/18
Username: JayRizzo
Description: My First Project Program.
# ==============================================================================

Notes: If you expand your program just set this once in the init.py and you should be all set, but again check with the professor.

If would like the script checkout my github.