code: def as_column(a):
      """
      Convert an array of shape (N,) into an array of shape (N, 1).
  
      This is equivalent to `a[:, np.newaxis]`.
  
      Parameters
      ----------
      a : np.ndarray
  
      Example
      -------
      >>> import numpy as np
      >>> a = np.arange(5)
      >>> a
      array([0, 1, 2, 3, 4])
      >>> as_column(a)
      array([[0],
             [1],
             [2],
             [3],
             [4]])
      >>> as_column(a).shape
      (5, 1)
      """
      if a.ndim != 1:
          raise ValueError(
              "as_column expected an 1-dimensional array, "
              "but got an array of shape %s" % (a.shape,)
          )
      return a[:, None]
  
imports: from collections import OrderedDict
  from datetime import datetime
  from distutils.version import StrictVersion
  from warnings import catch_warnings, filterwarnings
  import six
  import numpy
  from numpy import array_equal, broadcast, busday_count, datetime64, diff, dtype, empty, flatnonzero, hstack, isnan, nan, vectorize, where
  from numpy.lib.stride_tricks import as_strided
  from toolz import flip
label_desc: Use image node_id 16 for calling a global function with example usage: as_column(a) and returns: a