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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def set_font(self, font):

 """Set shell styles font"""

        self.setFont(font)
        self.set_pythonshell_font(font)
        cursor = self.textCursor()
        cursor.select(QTextCursor.Document)
        charformat = QTextCharFormat()
        charformat.setFontFamily(font.family())
        charformat.setFontPointSize(font.pointSize())
        cursor.mergeCharFormat(charformat)