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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 _ConvertFloat(value):
 """Convert an floating point number."""

  if value == 'nan':
    raise ParseError('Couldn\'t parse float "nan", use "NaN" instead.')
  try:
    # Assume Python compatible syntax.
    return float(value)
  except ValueError:
    # Check alternative spellings.
    if value == _NEG_INFINITY:
      return float('-inf')
    elif value == _INFINITY:
      return float('inf')
    elif value == _NAN:
      return float('nan')
    else:
      raise ParseError('Couldn\'t parse float: {0}.'.format(value))