Drawing China's Map with PySimpleGUI: Polygon Data and Code Example

The map of China consists of three closed polygons: the mainland, Hainan Island, and Taiwan. The data is stored in a plain‑text file that, when evaluated, yields a list containing three sub‑lists, each representing one of these regions as a collection of point groups.

Each point group is composed of two floating‑point arrays: longitude and latitude. Longitude values range from -180 to 180 (positive for east, negative for west) and latitude values range from -90 to 90 (positive for north, negative for south). Since all of China lies in the eastern and northern hemispheres, its coordinates are positive.

The following Python code uses PySimpleGUI to create a window with a graph canvas, reads the polygon data from china.txt , and draws each polygon in red:

import PySimpleGUI as sg
layout = [[sg.Graph(canvas_size=(800,800),
                    graph_bottom_left=(70,10),
                    graph_top_right=(140,60),
                    background_color="white",
                    float_values=True,
                    key='graph')]]
window = sg.Window('祖国山河一片红', layout, finalize=True)
with open('china.txt','r',encoding='utf-8') as f1:
    china = eval(f1.read())
    for shp in china:
        window['graph'].DrawPolygon(shp, fill_color='red')
event, values = window.read()

The script visualizes the entire Chinese territory as a single red shape, demonstrating a simple method for geographic data rendering using Python GUI libraries.