Can python turn strings into integers?

Why doesn’t Python concatenate strings with other data types like Java does?

Why can’t I do:
big_int = int(big_string)?

Some languages might have a representation of NotaNumber (NaN) which would be given if we attempt to cast a number from a string that cannot be cast. All Python can do is raise an exception.

>>> big_string = '10000000'
>>> big_int = int(big_string)
>>> big_int
>>> bigger_string = '1_000_000_000'
>>> bigger_int = int(bigger_string)

Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    bigger_int = int(bigger_string)
ValueError: invalid literal for int() with base 10: '1_000_000_000'