Creating a stem-and-leaf diagram/plot in 40~ lines of python code!

leaf_stem_diagram.py

# import time

def make_stemnleaf_diagram(data: list, no_of_spaces: int=3):
    # start_time = time.time()
    
    # Storing the list data as a dict
    dict_data = {}
    for i in data:
        i = str(i)
        starts = i[:-1]
        if not starts in dict_data:
            dict_data[starts] = []

        dict_data[starts].append(i[-1:])
    
    # Getting count the biggest length of the nums (for the spacing maths)
    biggest_num_len = len(sorted([*dict_data], key=len, reverse=True)[0])
    
    # Making the horizontal lines of the table
    main_format = "Stem" + " " * no_of_spaces + "Leaf\n"
    amt_of_lines = ""
    for i in range(len(main_format)):
        amt_of_lines += "-" if len(amt_of_lines)-2 != biggest_num_len else "+"
    amt_of_lines += "\n"
    main_format += amt_of_lines
    
    # Making the table itself
    for key, item_list in dict_data.items():
        
        if not len(key) == biggest_num_len:
            main_format += " {0}{1}|{2}{3}\n".format(key, " " * biggest_num_len, " " * (((biggest_num_len + no_of_spaces) - 2) - len(key)), " ".join([*sorted(item_list)]))
            
        else:
            main_format += " {0} |{1}{2}\n".format(key, " " * (((biggest_num_len + no_of_spaces) - 1) - len(key)), " ".join([*sorted(item_list)]))
        main_format += amt_of_lines
        
        
    # Print the table!
    print(main_format)
    # print("Finished in {}ms".format(round((time.time() - start_time) * 1000, 3)))
    
# Showing off outout
make_stemnleaf_diagram([10, 34, 38, 12, 56, 52, 53, 101, 104, 107, 32], 5)