AUX File Writing Error

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  • thewritersclub@gmail.com

    #1

    AUX File Writing Error

    Hi guys!

    I'm new to python so please be aware that I'm probably missing the
    obvious. Here's my problem...
    >>t = "AUX"
    >>f = open('c:\\' + t + '.csv', 'a')
    Traceback (most recent call last):
    File "<pyshell#3 7>", line 1, in <module>
    f = open('c:\\' + t + '.csv', 'a')
    IOError: [Errno 2] No such file or directory: 'c:\\AUX.csv'
    >>t = "A"
    >>f = open('c:\\' + t + '.csv', 'a')
    >>>
    As you can see python has no problem opening a file when t = "A", but
    not when it is "AUX" (no "A.csv" or "AUX.csv" exists on the C:\ folder
    prior to when these are run).

    Is there any way I can create an "AUX.csv" file without the error?

    Thanks,

    Ryan

  • John Machin

    #2
    Re: AUX File Writing Error

    On Feb 15, 4:03 pm, thewritersc...@ gmail.com wrote:
    Hi guys!
    >
    I'm new to python so please be aware that I'm probably missing the
    obvious. Here's my problem...
    >
    >t = "AUX"
    >f = open('c:\\' + t + '.csv', 'a')
    >
    Traceback (most recent call last):
    File "<pyshell#3 7>", line 1, in <module>
    f = open('c:\\' + t + '.csv', 'a')
    IOError: [Errno 2] No such file or directory: 'c:\\AUX.csv'
    >
    >t = "A"
    >f = open('c:\\' + t + '.csv', 'a')
    >
    As you can see python has no problem opening a file when t = "A", but
    not when it is "AUX" (no "A.csv" or "AUX.csv" exists on the C:\ folder
    prior to when these are run).
    >
    Is there any way I can create an "AUX.csv" file without the error?
    Probably not. AUX, CON, NUL, PRN, LPT, COM1, COM2 etc (with or without
    an extension) are reserved in Windows for specific devices for
    compatibility with MS-DOS 1.00 programs, which did that for
    compatibility with CP/M.

    HTH,
    John

    Comment

    • Gabriel Genellina

      #3
      Re: AUX File Writing Error

      En Thu, 15 Feb 2007 03:34:59 -0300, John Machin <sjmachin@lexic on.net>
      escribió:
      On Feb 15, 4:03 pm, thewritersc...@ gmail.com wrote:
      >Is there any way I can create an "AUX.csv" file without the error?
      >
      Probably not. AUX, CON, NUL, PRN, LPT, COM1, COM2 etc (with or without
      an extension) are reserved in Windows for specific devices for
      compatibility with MS-DOS 1.00 programs, which did that for
      compatibility with CP/M.
      (This is OT now) Do you know why "AUX.csv" is invalid too? I can accept
      that AUX (without extension) is an invalid filename, but it is quite
      different from "AUX.csv"

      --
      Gabriel Genellina

      Comment

      • Steve Holden

        #4
        Re: AUX File Writing Error

        Gabriel Genellina wrote:
        En Thu, 15 Feb 2007 03:34:59 -0300, John Machin <sjmachin@lexic on.net>
        escribió:
        >
        >On Feb 15, 4:03 pm, thewritersc...@ gmail.com wrote:
        >>Is there any way I can create an "AUX.csv" file without the error?
        >Probably not. AUX, CON, NUL, PRN, LPT, COM1, COM2 etc (with or without
        >an extension) are reserved in Windows for specific devices for
        >compatibilit y with MS-DOS 1.00 programs, which did that for
        >compatibilit y with CP/M.
        >
        (This is OT now) Do you know why "AUX.csv" is invalid too? I can accept
        that AUX (without extension) is an invalid filename, but it is quite
        different from "AUX.csv"
        >
        Because Windows is brain-dead? There really is no sense in looking for
        rationality where none exists. This is the way it is, and there's
        nothing you can do about it.

        regards
        Steve
        --
        Steve Holden +44 150 684 7255 +1 800 494 3119
        Holden Web LLC/Ltd http://www.holdenweb.com
        Skype: holdenweb http://del.icio.us/steve.holden
        Blog of Note: http://holdenweb.blogspot.com
        See you at PyCon? http://us.pycon.org/TX2007

        Comment

        • John Machin

          #5
          Re: AUX File Writing Error

          On Feb 16, 12:13 am, "Gabriel Genellina" <gagsl...@yahoo .com.ar>
          wrote:
          En Thu, 15 Feb 2007 03:34:59 -0300, John Machin <sjmac...@lexic on.net>
          escribió:
          >
          On Feb 15, 4:03 pm, thewritersc...@ gmail.com wrote:
          Is there any way I can create an "AUX.csv" file without the error?
          >
          Probably not. AUX, CON, NUL, PRN, LPT, COM1, COM2 etc (with or without
          an extension) are reserved in Windows for specific devices for
          compatibility with MS-DOS 1.00 programs, which did that for
          compatibility with CP/M.
          >
          (This is OT now) Do you know why "AUX.csv" is invalid too? I can accept
          that AUX (without extension) is an invalid filename, but it is quite
          different from "AUX.csv"
          >
          It is actually a valid file name, but the file is not on disk. I
          presume that the OP got an error because it was in 'a' (append) mode
          which requires an existing disk file. See below.

          C:\junk>copy con aux.csv
          fubar
          ^Z
          1 file(s) copied.

          C:\junk>copy con sux.csv
          fubar
          ^Z
          1 file(s) copied.

          C:\junk>dir *ux.csv
          [snip]
          Directory of C:\junk

          16/02/2007 01:19 AM 7 sux.csv
          1 File(s) 7 bytes

          Why? Who knows? We're talking CP/M, MS-DOS and Windows and you want to
          know why? Probably too lazy to distinguish between 'AUX\0', 'AUX.\0'
          and 'AUX.XYZ\0' ... probably stopped scanning on reaching the first
          invalid character. If you're desperate to find out, dial up your
          nearest RCPM and ask the sysop :-)

          Cheers,
          John

          Comment

          • Gabriel Genellina

            #6
            Re: AUX File Writing Error

            En Thu, 15 Feb 2007 11:34:53 -0300, John Machin <sjmachin@lexic on.net>
            escribió:
            Probably not. AUX, CON, NUL, PRN, LPT, COM1, COM2 etc (with or without
            an extension) are reserved in Windows for specific devices for
            compatibility with MS-DOS 1.00 programs, which did that for
            compatibility with CP/M.
            >>
            >(This is OT now) Do you know why "AUX.csv" is invalid too? I can accept
            >that AUX (without extension) is an invalid filename, but it is quite
            >different from "AUX.csv"
            >>
            >
            It is actually a valid file name, but the file is not on disk. I
            presume that the OP got an error because it was in 'a' (append) mode
            which requires an existing disk file. See below.
            >
            C:\junk>copy con aux.csv
            fubar
            ^Z
            1 file(s) copied.
            The above gives me an "Access denied" error; perhaps because AUX is my
            serial port and it is currently in use.
            Why? Who knows? We're talking CP/M, MS-DOS and Windows and you want to
            know why? Probably too lazy to distinguish between 'AUX\0', 'AUX.\0'
            and 'AUX.XYZ\0' ... probably stopped scanning on reaching the first
            invalid character. If you're desperate to find out, dial up your
            nearest RCPM and ask the sysop :-)
            Ahhhh... I think you hit the point, indirectly. On CP/M the filename was
            not stored as 'AUX\0' - remember, ONLY 8 characters plus 3 for extension,
            and NO PATH. A FileControlBloc k (FCB) had exactly 11 characters reserved
            for the file name (plus the drive number). So it was actually "AUX
            " vs "AUX XYZ" and... well, the lazyness argument again.

            --
            Gabriel Genellina

            Comment

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