Errata

Incorrect variable name inside the if __name__ block of code.
When executing the code python interpreter error:

File "<BASE_PATH>/sys_argv.py", line 34, in <module>
say_it(greeting, name)
NameError: name 'name' is not defined

Following change fixed the issue:

#!/usr/bin/env python3

"""
Simple command-line tool using sys.argv
"""

import sys

def say_it(greeting, target):
message = f'{greeting} {target}'
print(message)

if __name__ == '__main__':
greeting = 'Hello'
name = 'Joe' # <--- CHANGED from target to name

if '--help' in sys.argv:
help_message = f"Usage: {sys.argv[0]} --name <NAME> --greeting <GREETING>"
print(help_message)
sys.exit()

if '--name' in sys.argv:
# Get position after name flag
name_index = sys.argv.index('--name') + 1
if (name_index < len(sys.argv)):
name = sys.argv[name_index]

if '--greeting' in sys.argv:
# Get position after greeting flag
greeting_index = sys.argv.index('--greeting') + 1
if (greeting_index < len(sys.argv)):
greeting = sys.argv[greeting_index]

say_it(greeting, name)

The Chinese example 'Nǐn hǎo' has the wrong tone for 'Nin'. The example is confusing the more common, informal 'you', which is 'nǐ' (which is third tone) with respectful 'you' (nín) which is second tone (í) and not third tone (ǐ). Should either change 'Nǐn' to 'Nín' or use 'Nǐ'.