Python sample code to realize the combination of remote sensing image bands

from osgeo import gdal
import os
import numpy as np
 
class GRID:
 
  #Read image files
  def read_img(self,filename):
    dataset=(filename)    # Open the file
 
    im_width =   # of columns in the raster matrix
    im_height =   # of rows of the raster matrix
 
    im_geotrans = () # affine matrix
    im_proj = () # Map projection information
    im_data = (0,0,im_width,im_height) # Write the data as an array, corresponding to the raster matrix
 
    del dataset #Close object, file dataset
    return im_proj,im_geotrans,im_data,im_width,im_height
 
  #write file to write to tif for example
  def write_img(self,filename,im_proj,im_geotrans,im_data):
 
    # Determine the data type of raster data
    if 'int8' in im_data.:
      datatype = gdal.GDT_Byte
    elif 'int16' in im_data.:
      datatype = gdal.GDT_UInt16
    else:
      datatype = gdal.GDT_Float32
 
    # Interpretation of array dimensions
    if len(im_data.shape) == 3:
      im_bands, im_height, im_width = im_data.shape
    else:
      im_bands, (im_height, im_width) = 1,im_data.shape
 
    #Creating files
    driver = ("GTiff")  # Data types must be available because to calculate how much memory space is required
    dataset = (filename, im_width, im_height, im_bands, datatype)
 
    (im_geotrans)       #Write affine transformation parameters
    (im_proj)          #Write projection
 
    if im_bands == 1:
      (1).WriteArray(im_data) # Write array data
    else:
      for i in range(im_bands):
        (i+1).WriteArray(im_data[i])
 
    del dataset
 
if __name__ == "__main__":
  (r'E:\Python\temp\data')            # Switch the path to the folder where the image to be processed is located
  run = GRID()
  # First step
  proj,geotrans,data1,row1,column1 = run.read_img('Band_5_Clip.tif') #Read the data
  proj,geotrans,data2,row2,column2= run.read_img('Band_4_Clip.tif') # Read the data
  proj,geotrans,data3,row3,column3 = run.read_img('Band_3_Clip.tif') # Read the data
 
  # Step two
  data = ((data1, data2, data3),dtype = ) # Put the 3 band image element values in order into the
 
  # Step three
  run.write_img('', proj, geotrans, data) # put down as3Band data