[Tutor] Doubts galore.

[prasad rao]

> Never NEVER compare for equality with None.
>
>  What you want is:
>      if doc is None and data is None:
>
>  Also, what is "sys.agv1"?  Did you mean sys.argv[1]?
yes


>  >    elif doc:
>  >         data=open(doc,'r').read()
>  >         data_c= binascii.hexlify(data)
>  >    else:data_c= binascii.hexlify(data)
>  >    if doc:
>  >         q=tempfile.TemporaryFile()
>  >         q.write(data_c)
>  >         os.rename(q,doc)
>  >         return
>  >    return data_c


> It would probably be cleaner to use one-line
>  conditional statements (sparingly) where they make
>  sense on their own, but not to mix multi-line and
>  single line styles in the same if-else structure.

I am a newbie.I couldn't understand that comment.

>  I'm not sure the logical flow through there
>  does what you think it does, though.


>  > cript(doc='./language.txt')
>  > Traceback (most recent call last):
>  >   File "<stdin>", line 1, in <module>
>  >   File "<stdin>", line 10, in cript
>  > TypeError: coercing to Unicode: need string or buffer, file found



> Is this the actual code or did you retype it?

I just copied from .py file and pasted.

>  It has some typos which makes me wonder.  If you copy/paste
>  the actual code that can remove any confusion introduced
>  by simple typing mistakes, so we are sure we're all looking
>  at the same thing here.
>
>
>  > 1)Why I got the above error message with  the above function?How to correct it?
>
>
> The binascii.hexlify() function converts a binary data string into
>  hexadecimal digits.  You didn't give it a data string to work from,
>  you gave it an open file object.  You'll need to actually read the
>  data from the file and give that to the function.
>
>
>  > 2)Is it reasonable to have 2 if blocks in a function as above?
>
>
> Sure
>
>
>  > 3)Dose the tempfile create a fileobject on harddisk or in memory(Dose it save my
>  >   file as I expect it to do)
>
>
> It creates a TEMPORARY file.  That means you can expect it to
>  exist on disk until you close it, and then if at all possible,
>  it will automatically be destroyed for you.  Hence "temporary".
>  Depending on your platform, while there will be a physical disk
>  file, it might not even show up in a directory or be openable by
>  other applications.
>
>  If you want a file to not be temporary, use open() to create it.

>  Steve Willoughby    |  Using billion-dollar satellites
>  steve at alchemy.com   |  to hunt for Tupperware.

Thanks for the reply..Now I will try to correct my code.