Raising vs Reraising exceptions in python

>>> def foo(x):
...    raise Exception('%s is invalid input' % x)
...
>>> try:
...     foo(1)
... except Exception, e:
...     raise e                          # RE-RAISING EXCEPTIONS
...
Traceback (most recent call last):
  File "<stdin>", line 4, in <module>    # LOSES foo
Exception: 1 is invalid input
>>> try:
...     foo(1)
... except Exception:
...     raise                             # RAISING EXCEPTIONS
...
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
  File "<stdin>", line 2, in foo          # STORES foo too
Exception: 1 is invalid input
>>>

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