Refactoring the Charts class in rick.py

[MelinaGoula]

Context

The charts class in rick.py should be reformatted for better readability and ability to be generalized.

Potential improvements are:

• Replacing repeated code blocks with sub functions
• Updating functions to be able to support different input sizes, specifically, any bar or line charts should be able to handle more than just 1 or 2 columns of data
  • For example, bar_chart only supports graphing 2 columns of data but this could be extended to any number of columns
• Changing some class and function names for clarity

Outline of new structure

Plotting functions currently follow a relatively similar structure which could be replaced with the following functions (and potentially more):

calculate_y_params() # calculates the minimum, maximum and increment values for the y axis 
set_plot_style() # sets the grid, background color and size of the plot 
set_ticks() # sets the x and y ticks
set_labels() # sets x and y axis labels
set_annotations() # adds any additional annotations to the plot 
set_legend() # adds a legend to the plot 

Note: function arguments are in progress

A general plotting function would then follow the format below.

def example_plotting_function(df, ylab, xlab, **kwargs):
    '''
    Description of function including inputs, outputs and any kwargs. 
    '''
    func() # Should be renamed to be more clear 
    y_min, y_max, y_inc = calculate_y_params()
    fig, ax = example_plot() # depends on each function 
    fig, ax = set_plot_style() 
    fig, ax = set_ticks()
    fig, ax = set_labels()
    fig, ax = set_annotations()
    fig, ax = set_legend()
    return fig, ax

def example_plot(): 
	'''Description of function'''
	for i, col in data.columns: 
		## plot of specific type e.g. plot(data, ) for lines 

Furthermore, the Charts class can be reorganized to use inheritance such that:

• Charts contains all the functions that are common between the different chart types (the ones listed above) as methods
• Each chart type (e.g. line, bar chart) is a child class that includes it's own plotting method

class Charts:
	def calculate_y_params():

	def calculate_delta():

	def set_plot_style():

	def set_ticks():

	def set_labels():

	def set_annotations():
	
	def set_legend():

class LineChart(Charts): 
	def plot_line():

class BarChart(Charts): 
	def plot_bars():

To do

• Capitalize class names to follow CapWords convention
• Include docstrings / descriptions for all functions
• Rename the func function to make it more intuitive what it is doing (e.g. init_global_settings or something better)
• Create a plotting function for each chart type that can be generalized to any number of columns
• Create / update the methods of the Charts class to ensure that they work for any chart type