>>> mpf('1e400e2')
mpf('9.9999999999999997e+399')
>>> mpf('1e400f2')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Program Files\Python312\Lib\site-packages\mpmath\ctx_mp_python.py", line 69, in __new__
    val = cls.mpf_convert_arg(val, prec, rounding, base)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Program Files\Python312\Lib\site-packages\mpmath\ctx_mp_python.py", line 77, in mpf_convert_arg
    if isinstance(x, str): return from_str(x, prec, rounding, base)
                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Program Files\Python312\Lib\site-packages\mpmath\libmp\libmpf.py", line 1292, in from_str
    man, exp = str_to_man_exp(x, base)
               ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Program Files\Python312\Lib\site-packages\mpmath\libmp\libmpf.py", line 1239, in str_to_man_exp
    exp = int(parts[1])
          ^^^^^^^^^^^^^
ValueError: invalid literal for int() with base 10: '400f2'