Please explain this Python code def trigrams(ls,t): # counts user supplied trigram trioccurs = 0 # loop through longstring counting occurences of target for lc in range(0,len(ls)-2): if ls[lc:lc+3] == t: trioccurs += 1 return trioccurs def trigrams(ls): # uses a dictionary; finds all trigrams dict = {} # loop through longstring counting occurences of target for lc in range(0,len(ls)-2): t = ls[lc:lc+3] # if not there, insert into dictionary if t not in dict: dict[t] = 1 else: dict[t] = dict[t] + 1 return dict

get_top_regions() that takes three input parameters; the 2-D list (similar to the database), the dictionary that stores information of all regions, and a non-zero positive integer x. This function returns a new dictionary that contains the information of top-x regions in terms of the total number of hospitalization cases recorded in these regions. That means these top-x regions have the largest numbers of hospitalization cases. Each {key:value} pair in this resulting dictionary stores the name of a top region as the key and the value is the total number of hospitalization cases reported in this region. The result does not need to be sorted, the regions of the resulting dictionary can appear in any order as long as the top-x regions have been identified correctly. If the value of x is less than 1, or more than the total number of unique regions, your function should print a message informing the user and return an empty dictionary. See sample outputs below. >>> topx_regions…

IntSet unionWith(const IntSet& otherIntSet) const; //Unions the current set with the passed set.  IntSet::unionWith(const IntSet& otherIntSet){    for (int i = 0; i < otherIntSet.used; ++i)    //For each element in the passed set.    {        add(otherIntSet.data[i]);    //Add it to current set.    }}

Python question, need some help