Might be useful...
Using python 2.7.12 and ReportLab 3.5.31, "from reportlab.graphics.barcode import qr" causes errors, I think it's because rl_exec imports later.
hiddenimports=[
'reportlab.graphics.barcode.common',
'reportlab.graphics.barcode.code128',
'reportlab.graphics.barcode.code93',
'reportlab.graphics.barcode.code39',
'reportlab.graphics.barcode.code93',
'reportlab.graphics.barcode.usps',
'reportlab.graphics.barcode.usps4s',
'reportlab.graphics.barcode.ecc200datamatrix',
],