def replace_float_digit(number: float, position: int, new_digit: str) -> float:
# Validate that newDigit is indeed a single digit
if not new_digit.isdigit() or len(new_digit) != 1:
raise ValueError("Replacement must be a single digit (0-9).")
# Convert number to string with fixed precision (10 decimal places)
str_num = f"{number:.10f}"
# Validate position
if position < 0 or position >= len(str_num):
raise IndexError("Position is out of range for the number string.")
# Ensure position points to a digit
if str_num[position] in ('.', '-'):
raise ValueError("Position points to a non-digit character.")
# Replace digit
modified = str_num[:position] + new_digit + str_num[position+1:]
# Convert back to float
return float(modified)
def main():
try:
num = 89710.291
pos = 2 # 0-based index
new_digit = '8'
result = replace_float_digit(num, pos, new_digit)
print(f"Modified number: {result:.3f}")
except Exception as e:
print(f"Error: {e}")
if __name__ == "__main__":
main()
'''
run:
Modified number: 89810.291
'''
