A simple Python graphing tool

Question

I've written a primitive Python script which "draws graphs" based on a list. It works, but it's a lot of lines for what I am trying to reach. The idea of the script is to function as a module that can be imported for a quick visual representation of data. Here's nextgraph.py:

from time import sleep

def draw_graph(
               x,
               y,
               previous=None, 
               initial=None,
               header_margin=1,
               footer_margin=1,
               anim_time=0.5,
               graph_symbol="*",
               indicator="|",
               graph_subtitle="My graph"
              ):

    if initial:
        graph_ = initial
        initial[x[y]][y] = graph_symbol
        # This may be a bit confusing, in this case,
        # x[y] means the current integer in a list (x)
        # and not "x-coordinate[y-coordinate]"

    else:
        graph_ = previous
        graph_[x[y]][y] = graph_symbol
        # Same thing here

    sleep(anim_time)        
    print(
          "\n"*header_margin,          
                indicator.join(graph_[0]), 
          "\n", indicator.join(graph_[1]),
          "\n", indicator.join(graph_[2]), 
          "\n", indicator.join(graph_[3]), 
          "\n", indicator.join(graph_[4]),
          "\n", indicator.join(graph_[5]), 
          "\n", indicator.join(graph_[6]), 
          "\n", indicator.join(graph_[7]),
          "\n", indicator.join(graph_[8]), 
          "\n", indicator.join(graph_[9]), 
          "\n", indicator.join(graph_[10]),
          "\n", indicator.join(graph_[11]), 
          "\n", indicator.join(graph_[12]), 
          "\n", indicator.join(graph_[13]),
          "\n", indicator.join(graph_[14]), 
          "\n", indicator.join(graph_[15]), 
          "\n", indicator.join(graph_[16]),
          "\n", indicator.join(graph_[17]),
          graph_subtitle,
          "\033[00m",
          "\n"*footer_margin)

    return graph_


def update_graph(data,
                 top,
                 bottom,
                 sleep_,
                 color="\033[00m",
                 symbol="*",
                 seperator="|",
                 comment="My graph"
                 ):

    graph = [
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "], 
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "], 
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "],
            [" ", " ", " ", " ", " ", " ", " ", " ", " ",
             " ", " ", " ", " ", " ", " ", " ", " ", " "]
            ]

    markers = 0
    while markers != 17:
        print("\033[00m")
        for _ in data:
            print(color)
            if markers == 0:
                old = draw_graph(data,
                                 markers, 
                                 initial=graph,
                                 header_margin=top,
                                 footer_margin=bottom,
                                 anim_time=sleep_,
                                 graph_symbol=symbol,
                                 indicator=seperator,
                                 graph_subtitle=comment
                                )


            else:
                old = draw_graph(data, 
                                 markers, 
                                 old,
                                 header_margin=top,
                                 footer_margin=bottom,
                                 anim_time=sleep_,
                                 graph_symbol=symbol,
                                 indicator=seperator,
                                 graph_subtitle=comment
                                )

            markers += 1

        print("\033[00m")

And here's a sample implementation (GraphTest.py):

from nextgraph import update_graph
from time import time

stream = [

          [3,3,3,3,4,4,4,3,3,3,3,4,3,2,1,2,2],
          [2,3,4,5,5,6,5,6,5,6,6,7,8,8,9,10,9],
          [10,11,12,13,13,14,14,15,14,14,13,12,11,10,9,8,7],
          [7,7,7,8,8,7,7,7,6,5,5,4,5,3,1,2,2],
          [3,3,4,3,4,3,4,5,6,6,5,4,3,2,1,1,2]

         ]

count = 0

for substream in stream:
    update_graph(data=substream,
                 top=30,
                 bottom=8,
                 sleep_=0.2
                )
    count += 1

I am having trouble getting this to be more scalable. Adding a row/column would currently require adding another two lines to the code, so for a larger number (128 / 256 positions), this would become unmanageable. Also, for each added row, the print() function in draw_graph needs another line. If anybody has any suggestions on how to simplify the graph matrix or draw_graph / update_graph functions, or otherwise on how to improve the code, I'd love to hear.

Answer 1

• You may want to change update_graph so that it uses *args and **kwargs. update_graph(data, *args, color="\033[00m", **kwargs). This would allow you to then call draw_graph with less arguments, all on the same line:

  if markers == 0:
      old = draw_graph(data, markers, *args, initial=graph, **kwargs)
  else:
      old = draw_graph(data, markers, *args, previous=old, **kwargs)
  

• Rather than manually building the graph, you can instead use a comprehension and *. graph = [[" "] * 18 for _ in range(18)]. This is much more readable, and takes up much less space.

• Rather than manually joining all the lines in the graph, you could instead use join each line with " \n " as that's what , "\n", is doing. This assumes that graph_ is only 18 lines high.

  " \n ".join(indicator.join(g) for g in graph_)
  

• You could probably also use use iter and next, rather than using markers == 0, however that's may be less readable to you.

• Rather than using graph_ = initial and graph_ = previous you could just pass graph_ this would remove the if's in both update_graph and draw_graph. As they're doing the same thing.

• You may want to create an enum of colours, rather than using magic strings, such as "\033[00m".