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Groups > comp.lang.python > #8980

Re: Does hashlib support a file mode?

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On Wed, Jul 6, 2011 at 1:07 PM, Phlip <phlip2005@gmail.com> wrote:
> If I call m = md5() twice, I expect two objects.
>
> I am now aware that Python bends the definition of "call" based on
> where the line occurs. Principle of least surprise.

There is no definition-bending.  The code:

"""
def file_to_hash(path, m = hashlib.md5()):
    # do stuff...

file_to_hash(path1)
file_to_hash(path2)
"""

does not call hashlib.md5 twice.  It calls it *once*, at the time the
file_to_hash function is defined.  The returned object is stored on
the function object, and that same object is passed into file_to_hash
as a default value each time the function is called.  See:

http://docs.python.org/reference/compound_stmts.html#function

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Re: Does hashlib support a file mode? Phlip <phlip2005@gmail.com> - 2011-07-06 12:07 -0700
  Re: Does hashlib support a file mode? geremy condra <debatem1@gmail.com> - 2011-07-06 15:15 -0400
  Re: Does hashlib support a file mode? Andrew Berg <bahamutzero8825@gmail.com> - 2011-07-06 14:42 -0500
  Re: Does hashlib support a file mode? Mel <mwilson@the-wire.com> - 2011-07-06 15:43 -0400
    Re: Does hashlib support a file mode? Anssi Saari <as@sci.fi> - 2011-07-07 14:29 +0300
      Re: Does hashlib support a file mode? Paul Rudin <paul.nospam@rudin.co.uk> - 2011-07-07 13:13 +0100
  Re: Does hashlib support a file mode? Ian Kelly <ian.g.kelly@gmail.com> - 2011-07-06 13:48 -0600
  Re: Does hashlib support a file mode? Ethan Furman <ethan@stoneleaf.us> - 2011-07-06 13:24 -0700

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