code: def num_combinations(n, k, with_replacement=False):
      """
      Function to calculate the number of possible combinations.
  
      Parameters
      ----------
      n : `int`
          Total number of items.
      k : `int`
          Number of elements of the target itemset.
      with_replacement : `bool` (default: False)
          Allows repeated elements if True.
  
      Returns
      ----------
      comb : `int`
          Number of possible combinations.
  
      Examples
      -----------
      For usage examples, please see
      https://rasbt.github.io/mlxtend/user_guide/math/num_combinations/
  
      """
      if with_replacement:
          numerator = factorial(n + k - 1)
          denominator = factorial(k) * factorial(n - 1)
      else:
          numerator = factorial(n)
          denominator = factorial(k) * factorial(n - k)
      comb = numerator // denominator
      return comb
  
label_desc: Use image node_id 2 for calling a global function with example usage: num_combinations(n, k, with_replacement) and returns: comb