how to define report file name automatly

[tjdals7244]

I am trying to name my report file automate using this code

part of my code is

battery_short_resistance_list = [1e-09]
report_definitions = [
"cell-echem-heat-source",
"short-heat-source",
"total-heat-source",
"battery-terminal-current",
"battery-terminal-voltage",
"flow-time",
]
file_naming = f"nail_{battery_short_resistance:.1e}"

# report_files = solver.solution.monitor.report_files
# report_files.create("nail") ==  {}
# report_files("nail") == {
#     "report_defs" : ["flow-time", "soc", "cell-echem-heat-source", "short-heat-source", "total-heat-source"],
#     "file_name": r"nail_{file_naming}.out",
#     }
# print(f"Report file writing: {file_naming}")

but this doesn't work. Can I know why?