How to plot points in a shapefile in Python

1   Introduction

We want to plot all the points in Points.zip using matplotlib.

2   Python code

from osgeo import ogr
from matplotlib import pyplot as plt

file = ogr.Open("p:/courses/python/points.shp")
lyr = file.GetLayer(0)
x = []
y = []
for i in range(lyr.GetFeatureCount()):
    feat = lyr.GetFeature(i)
    geom = feat.geometry()
    pnt = geom.GetPoint()
    x.append(pnt[0])
    y.append(pnt[1])

for i in range(1, len(x)):
    plt.plot([x[0], x[i]], [y[0], y[i]])

plt.show()

3   Homework: Write the find_nearest function

Write a Python function called find_nearest that returns the index of the neighbor feature that is closest to the first feature at index 0. This function should

• take one argument shp_path, which is equivalent to "p:/courses/python/points.shp" in the exercise,
• open this shapefile at shp_path,
• read all the features,
• calculate distances,
• find the nearest feature from the first feature, and
• return its index.

Use the same Points.shp from the exercise above. Please submit your function in FirstLastname_find_nearest.py.