SystemError: Bad call flags in PyCFunction_Call. METH_OLDARGS is no longer supported! about pythonqwt HOT 8 CLOSED

I have tested this part of the code with the following script with Python 2.7 and Python 3.4 and it works:
(what version of Python 3 are you using?)

import struct
from qwt.qt.QtGui import (QApplication, QColor, QFont, QPixmap, QFontMetrics,
                          QPainter)
from qwt.qt.QtCore import Qt

def findAscent(font):
    dummy = "E"
    white = QColor(Qt.white)
    fm = QFontMetrics(font)
    pm = QPixmap(fm.width(dummy), fm.height())
    pm.fill(white)
    p = QPainter(pm)
    p.setFont(font)
    p.drawText(0, 0, pm.width(), pm.height(), 0, dummy)
    p.end()
    img = pm.toImage()
    w = pm.width()
    linebytes = w*4
    for row in range(img.height()):
        line = img.scanLine(row).asstring(linebytes)
        for col in range(w):
            color = struct.unpack('I', line[col*4:(col+1)*4])[0]
            if color != white.rgb():
                return fm.ascent()-row+1
    return fm.ascent()

if __name__ == '__main__':
    app = QApplication([])
    font = QFont('Arial')
    print(findAscent(font))

from pythonqwt.

Tested on Python 3.3 on Windows 10. It works too.

from pythonqwt.

com-sixs@sixs7:~/picca/bugs$ python3.4 test.py
Traceback (most recent call last):
File "test.py", line 30, in
print(findAscent(font))
File "test.py", line 20, in findAscent
line = img.scanLine(row).asstring(linebytes)
SystemError: Bad call flags in PyCFunction_Call. METH_OLDARGS is no longer supported!

from pythonqwt.

I split the line and it failes with the asstring method

Traceback (most recent call last):
File "test.py", line 32, in
print(findAscent(font))
File "test.py", line 22, in findAscent
line = sline.asstring(linebytes)
SystemError: Bad call flags in PyCFunction_Call. METH_OLDARGS is no longer supported!

from pythonqwt.

https://bugs.python.org/issue15657

I think that there is a bad interaction with sip

from pythonqwt.

https://riverbankcomputing.com/pipermail/pyqt/2014-December/035201.html

from pythonqwt.

Ok, I think you found the source of the problem.

Given the fact that Phil Thompson wrote here that the bug was fixed in latest sip snapshot on december 2014, it should be fixed with PyQt4 >= 4.11.4 and PyQt5 >= 5.4.

So the question is: what version of PyQt are you using? and would it be possible for you to upgrade your PyQt installation?

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ii python-sip 4.16.4+dfsg-1 amd64 Python/C++ bindings generator runtime library
ii python3-sip 4.16.4+dfsg-1 amd64 Python 3/C++ bindings generator runtime library
picca@sixs7:~/Debian/guiqwt$ dpkg -l | grep python-qt4
ii python-qt4 4.11.2+dfsg-1 amd64 Python bindings for Qt4
ii python-qt4-gl 4.11.2+dfsg-1 amd64 Python bindings for Qt4's OpenGL module

The current Debian jessie is affected by this bug :((. It means that for now it is not possible to backport the python3 version of python-qwt. Not a big deal, but it is nice to have the info somewhere :)

thanks

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