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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 as_series(x):
 """Cast as pandas Series. Cast an iterable to a Pandas Series object. Note that the index will simply be a positional ``arange`` and cannot be set in this function. Parameters x : array-like, shape=(n_samples,) The 1d array on which to compute the auto correlation. Examples -------- 0 1 1 2 2 3 dtype: int64 0 1 1 2 2 3 dtype: int64 a 4 b 5 c 6 dtype: int64 Returns ------- s : pd.Series A pandas Series object. """

    if isinstance(x, pd.Series):
        return x
    return pd.Series(column_or_1d(x))