+def add_thousands_separator(in_str: str, *, separator_char = ',', places = 3) -> str:
+ if isinstance(in_str, int):
+ in_str = f'{in_str}'
+
+ if is_number(in_str):
+ return _add_thousands_separator(
+ in_str,
+ separator_char = separator_char,
+ places = places
+ )
+ raise ValueError(in_str)
+
+
+def _add_thousands_separator(in_str: str, *, separator_char = ',', places = 3) -> str:
+ decimal_part = ""
+ if '.' in in_str:
+ (in_str, decimal_part) = in_str.split('.')
+ tmp = [iter(in_str[::-1])] * places
+ ret = separator_char.join(
+ "".join(x) for x in zip_longest(*tmp, fillvalue=""))[::-1]
+ if len(decimal_part) > 0:
+ ret += '.'
+ ret += decimal_part
+ return ret
+
+