Performance evaluation of three ways to format a string with values stored in a dictionary

dict_fstring_or_format.py

import timeit


def v_fstring(row):
    return f"{row['group']}.{row['sub']}.{row['num']:05}"

def v_format(row):
    return "{group}.{sub}.{num:05}".format(**row)


def v_var_fstring(row):
    group = row['group']
    sub = row['sub']
    num = row['num']
    return f"{group}.{sub}.{num:05}"


def test(func, number, time_base=None):
    func_time = timeit.timeit(lambda : func(row), number=number)
    compare_time = func_time/time_base*100 if time_base else 100
    print(f"{func_time:.4f}", func.__name__, f"{compare_time:.1f}%")
    return func_time


row = {
    'group': 'ggg',
    'sub': 'mm',
    'num': 1,
}

number=10000000

time_base = test(v_fstring, number)

test(v_format, number, time_base)

test(v_var_fstring, number, time_base)

# output
# 6.6437 v_fstring 100.0%
# 9.5317 v_format 143.5%
# 6.9131 v_var_fstring 104.1%