extracting IndirectObject stream

I have a pdf file, and this is the snippet which concernes me:

558 0 obj
<</Contents 583 0 R/CropBox[0 0 595.22 842]/MediaBox[0 0 595.22 842]/Parent 29 0 R/Resources
  <</ColorSpace <</CS0 563 0 R>>
    /ExtGState <</GS0 568 0 R>>
    /Font<</TT0 559 0 R/TT1 560 0 R/TT2 561 0 R/TT3 562 0 R>>
    /ProcSet[/PDF/Text/ImageC]
    /Properties<</MC0<</MYOBJECT 584 0 R>>/MC1<</SubKey 582 0 R>> >>
    /XObject<</Im0 578 0 R>>>>
  /Rotate 0/StructParents 0/Type/Page>>
endobj
...
...
...
584 0 obj
<</Length 8>>stream

1_22_4_1 --->>>> this is the string I need to extract from the stream

endstream
endobj

I need to extract the stream associated to the IndirectObject named MYOBJECT, that is the string 1_22_4_1.
I am able to find the IndirectObject by this way:

pdfFile = pyPdf.PdfFileReader(open("file.pdf"))
pageData = pdfFile.getPage(0)["/Resources"]["/Properties"] # page 0 because this stream is saved ever in the first page
for x in pageData:
  if "/MYOBJECT" in pageData[x].keys():
    indirectObject = pageData[x].get('/MYOBJECT')
print indirectObject

this code gives me this output:

IndirectObject(584, 0)

I agree that this couldn't be the best way to find it, but it was only a try.
Can you tell me if I am able to get the stream associated to the key MYOBJECT? And, if you want, can you tell me how to change my code for best results

Thanks in advance,