Sometimes you need to ask the user for the input (Wi-Fi password, station name, etc). Python has a built-in input() function for this case.
See the example below on how to read a user name and set it to the USER_NAME macro.
platformio.ini:
[env:my_env]
platform = ...
extra_scripts = extra_script.py
extra_script.py:
Import("env")
# Do not run a script when external applications, such as IDEs,
# dump inetgration data. Otherwise, input() will block the process
# waiting for the user input
if env.IsIntegrationDump():
# stop the current script execution
Return()
# Ask user name
print("Enter your name:")
user_name = input()
env.Append(
CPPDEFINES=[("USER_NAME", f'\\"{user_name}\\"')],
)