EBCDIC translation?

Thu Mar 9 04:03:39 EST 2000

Steve Moon wrote:
> 
> Hi,
> 
> I have several binary EBCDIC files from a mainframe I need to read. I
> would like to use Python. Are there any libraries available for this?
> 
> A good start would be an ASCII <--> EBCDIC translation.
> 

I doubt that the Ebcdic and Ascii characters cover exactly the same set.
The following approximation is what I found laying about about here
(no guarantees):

Al

----------------------------------------------------------------------

import string

def ebcdicPlusStripperFunc():
    return string.maketrans( 'ABCDEFGHI{', '1234567890' )

def ebcdicMinusStripperFunc():
    return string.maketrans( 'JKLMNOPQR}', '1234567890' )

def ebcdicMinusAdderFunc():
    return string.maketrans( '1234567890','JKLMNOPQR}'  )

def asciiMinusStripperFunc():
    return string.maketrans(  chr(33) + chr(34) + chr(35)
                            + chr(36) + chr(37) + chr(38)
                            + chr(39) + chr(40) + chr(41)
                            + chr(32), '1234567890' )

ebcdicPlusStripperString  = ebcdicPlusStripperFunc()
ebcdicMinusStripperString = ebcdicMinusStripperFunc()
asciiMinusStripperString  = asciiMinusStripperFunc()
ebcdicMinusAdderString    = ebcdicMinusAdderFunc()

def stripSign( s ):
    signByte = s[-1]
    if ( signByte >= '0' ) and ( signByte <= '9' ):
        return ( s, 1 )
    x = string.translate( signByte, ebcdicPlusStripperString )
    if x != signByte:
        return ( s[:-1] + x, 1 ) 
    x = string.translate( signByte, ebcdicMinusStripperString )
    if x != signByte:
        return ( s[:-1] + x, -1 ) 
    x = string.translate( signByte, asciiMinusStripperString )
    if x != signByte:
        return ( s[:-1] + x, -1 ) 
    else:
        return ( s, 1 )

def pic9Decimal( s, decimals ):
    ( s, theSign ) = stripSign( s )
    x = float( s + '.0' )
    denominator = 1.0
    for i in range( decimals ):
        denominator = denominator * 10.0
    return theSign * x / denominator        

def pic9Integer( s ):
    ( s, theSign ) = stripSign( s )
    return theSign * int( s )

def toEbcdicTranslaterFunc():
    asciiToEbcdicIntegers = [
          0,  1,  2,  3, 55, 45, 46, 47, 22,  5, 37, 11, 12, 13, 14, 15,

         16, 17, 18, 19, 60, 61, 50, 38, 24, 25, 63, 39, 28, 29, 30, 31,

         64, 79,127,123, 91,108, 80,125, 77, 93, 92, 78,107, 96, 75, 97,

        240,241,242,243,244,245,246,247,248,249,122, 94, 76,126,110,111,

        124,193,194,195,196,197,198,199,200,201,209,210,211,212,213,214,

        215,216,217,226,227,228,229,230,231,232,233, 74,224, 90, 95,109,

        121,129,130,131,132,133,134,135,136,137,145,146,147,148,149,150,

        151,152,153,162,163,164,165,166,167,168,169,192,106,208,161,  7,

         32, 33, 34, 35, 36, 21,  6, 23, 40, 41, 42, 43, 44,  9, 10, 27,

         48, 49, 26, 51, 52, 53, 54,  8, 56, 57, 58, 59,  4, 20, 62,225,

         65, 66, 67, 68, 69, 70, 71, 72, 73, 81, 82, 83, 84, 85, 86, 87,

         88, 89, 98, 99,100,101,102,103,104,105,112,113,114,115,116,117,

        118,119,120,128,138,139,140,141,142,143,144,154,155,156,157,158,

        159,160,170,171,172,173,174,175,176,177,178,179,180,181,182,183,

        184,185,186,187,188,189,190,191,202,203,204,205,206,207,218,219,

        220,221,222,223,234,235,236,237,238,239,250,251,252,253,254,255
]

    asciiToEbcdicChars = []

    for i in asciiToEbcdicIntegers:
        asciiToEbcdicChars.append( chr(i) )
    return string.join( asciiToEbcdicChars, '' )         

toEbcdicTranslater = toEbcdicTranslaterFunc()

def toEbcdic( s ):
    return string.translate( s, toEbcdicTranslater )

def toAsciiTranslaterFunc():
    ebcdicToAsciiIntegers = [
          0,  1,  2,  3,156,  9,134,127,151,141,142, 11, 12, 13, 14, 15,

         16, 17, 18, 19,157,133,  8,135, 24, 25,146,143, 28, 29, 30, 31,

        128,129,130,131,132, 10, 23, 27,136,137,138,139,140,  5,  6,  7,

        144,145, 22,147,148,149,150,  4,152,153,154,155, 20, 21,158, 26,

         32,160,161,162,163,164,165,166,167,168, 91, 46, 60, 40, 43, 33,

         38,169,170,171,172,173,174,175,176,177, 93, 36, 42, 41, 59, 94,

         45, 47,178,179,180,181,182,183,184,185,124, 44, 37, 95, 62, 63,

        186,187,188,189,190,191,192,193,194, 96, 58, 35, 64, 39, 61, 34,

        195, 97, 98, 99,100,101,102,103,104,105,196,197,198,199,200,201,

        202,106,107,108,109,110,111,112,113,114,203,204,205,206,207,208,

        209,126,115,116,117,118,119,120,121,122,210,211,212,213,214,215,

        216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,

        123, 65, 66, 67, 68, 69, 70, 71, 72, 73,232,233,234,235,236,237,

        125, 74, 75, 76, 77, 78, 79, 80, 81, 82,238,239,240,241,242,243,

         92,159, 83, 84, 85, 86, 87, 88, 89, 90,244,245,246,247,248,249,

         48, 49, 50, 51, 52, 53, 54, 55, 56, 57,250,251,252,253,254,255
]

    ebcdicToAsciiChars = []
    for i in ebcdicToAsciiIntegers:
        ebcdicToAsciiChars.append( chr(i) )
    return string.join( ebcdicToAsciiChars, '' )         

toAsciiTranslater = toAsciiTranslaterFunc()

def toAscii( s ):
    return string.translate( s, toAsciiTranslater )

def addEbcdicMinusZone( s ):
    return s[:-1] + string.translate( s[-1], ebcdicMinusAdderString )

def makeEbcdicPic9Integer( x, width ):
    try:
        if x < 0:
            isMinus = 1
            x = -x
        else:
            isMinus = 0
        answer = "%015d" % (x,)
        answer = answer[-width:]
        if isMinus:
            return addEbcdicMinusZone( answer )
        else:
            return answer
    except:
        print "Error Formatting Ebcdic Integer", `x`, `width`

def makeEbcdicPic9Decimal( x, width, decimals ):
    try:
        if x < 0:
            isMinus = 1
            x = -x
        else:
            isMinus = 0
        answer = "%031.15f" % (x,)
        answer = answer[15-width+decimals:15] + answer[16:16+decimals]
        if isMinus:
            return addEbcdicMinusZone( answer )
        else:
            return answer
    except:
        print "Error Formatting Ebcdic Decimal",`x`,`width`,`decimals`