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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 _guessEncoding(self, path):
 """Opens a file from the given `path` and checks the file encoding. The file must exists on the file system and end with the extension `.csv`. The file is read line by line until the encoding could be guessed. On a successfull identification, the widgets of this dialog will be updated. Args: path (string):
 Path to a csv file on the file system. """

        if os.path.exists(path) and path.lower().endswith('csv'):
            # encoding = self._detector.detect(path)
            encoding = None

            if encoding is not None:
                if encoding.startswith('utf'):
                    encoding = encoding.replace('-', '')
                encoding = encoding.replace('-','_')

                viewValue = _encodings.get(encoding)

                self._encodingKey = encoding

                index = self._encodingComboBox.findText(viewValue.upper())
                self._encodingComboBox.setCurrentIndex(index)