def addKeysWithoutValueToDict(valDict, keyArray):
  """This function adds keys from keyArray to valDict in case it does not exist yet, the default value is an empty string

  >>> addKeysWithoutValueToDict({'a': 'valA', 'b': 'valB'}, ['a', 'b', 'c'])
  {'a': 'valA', 'b': 'valB', 'c': ''}
  """

  for key in keyArray:
    if key not in valDict:
      valDict[key] = ''
  return valDict