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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 getcolkeyword(self, columnname, keyword):
 """Get the value of a column keyword. It is similar to :func:`getkeyword`. """

        if isinstance(keyword, str):
            return self._getkeyword(columnname, keyword, -1)
        else:
            return self._getkeyword(columnname, '', keyword)