Question

I have a CsvWriter class that inherits from a Writer class. The Writer class has a function getInfo that I want to use in multiple ‘child’ classes. But when I call the getInfo function from the CsvWriter class I get this error:

TypeError: unbound method getInfo() must be called with Writer instance as first argument (got Element instance instead)

So because the Writer class hasn’t been intansiated yet, I can’t call getInfo. But I don’t want to instantiate it (I think), because I want to call it from a ‘child’ class. How can I call that function from CsVwriter()?

Below are the two classes:

class Writer():
    def __init__(self, path, readerInstance):
        self.path = path
        self.readerInstance = readerInstance
        return

    def getInfo(self, element):
        print element


class CsvWriter(Writer):
    def __init__(self,path, readerInstance):
        self.path = path
        self.readerInstance = readerInstance
        for feature in readerInstance.getFeatures():
            Writer.getInfo(feature)
        return

I run them like this:

filePath = '/homes/ndeklein/test.featureXML'
elements = featXML.Reader(filePath)
featXML.CsvWriter('test.csv', elements)

Answer 1

Replace Writer.getInfo() with self.getInfo().