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pythonfor-loopmkdir

How to save different images into different directories in python?


I want to save 4 images in 4 directories and name of directories are 4,5,6,7 (for instance image 1 in directory 4 and image 2 in directory 5 and so on) but it seems my for loop it's not correct and just saves the last image in directory 4.

import numpy as np
import matplotlib.pyplot as plt
import os

pixels = 600
my_dpi = 100
num_geo=3

coord = np.array([[[-150, -200], [300, -200], [300, 0], [150, 200], [-150, 200]],
                  [[-300, -200], [200, -300], [200, -50], [200, 300], [-150, 200]],
                  [[-140, -230], [350, -260], [350, 0], [140, 200], [-180, 220]],
                  [[-180, -240], [370, -270], [370, 0], [170, 200], [-190, 230]]])

for i in range(4):
    geo = coord[i, :, :]
    print(coord[i])
    fig = plt.figure(num_geo,figsize=( pixels/my_dpi,  pixels/my_dpi),facecolor='k', dpi=my_dpi)  
    plt.axes([0,0,1,1])
    rectangle = plt.Rectangle((-300, -300), 600, 600, fc='k')
    plt.gca().add_patch(rectangle)
    polygon = plt.Polygon(coord[i],color='w')
    plt.gca().add_patch(polygon)
    plt.axis('off')
    plt.axis([-300,300,-300,300])
for j in range(4,8):  
    os.mkdir("fig/%d" % j)
    plt.savefig('fig/%d/%d.jpg' % (j,i), dpi=my_dpi)
    plt.close()

Solution

  • You don't need second loop - besides it runs after first loop when i has value 4 so you get all images in directory 4

    You need j = i + 4

    for i in range(4):
        geo = coord[i, :, :]
        print(coord[i])
        fig = plt.figure(num_geo,figsize=( pixels/my_dpi,  pixels/my_dpi),facecolor='k', dpi=my_dpi)  
        plt.axes([0,0,1,1])
        rectangle = plt.Rectangle((-300, -300), 600, 600, fc='k')
        plt.gca().add_patch(rectangle)
        polygon = plt.Polygon(coord[i],color='w')
        plt.gca().add_patch(polygon)
        plt.axis('off')
        plt.axis([-300,300,-300,300])
        j = i + 4
        os.mkdir("fig/%d" % j)
        plt.savefig('fig/%d/%d.jpg' % (j,i), dpi=my_dpi)
        plt.close()