Make GTiff with GDAL but the result is VRT

Question

I tried to make raster file with GTiff format by using python GDAL, this is my sample gdal logic:

driver = gdal.GetDriverByName('GTiff')
outRaster = driver.Create(raster_classified, col, row, 1, gdal.GDT_Int16)
outRaster.SetGeoTransform((origin_x, cell_size, 0, origin_y - (cell_size * row), 0, cell_size))
outband = outRaster.GetRasterBand(1)
outband.WriteArray(outras_array[::-1])
outRasterSRS = osr.SpatialReference()
outRasterSRS.ImportFromEPSG(4326)
outRaster.SetProjection(outRasterSRS.ExportToWkt())
outband.FlushCache()

But after the raster file was created.. it's return with VRT format.. why? This is the raster properties :

Driver
GDAL provider
VRT
Virtual Raster
Dataset Description
Band 1
STATISTICS_MAXIMUM=9
STATISTICS_MEAN=0.99751150063449
STATISTICS_MINIMUM=0
STATISTICS_STDDEV=2.3322020706147
Dimensions
X: 6500 Y: 4500 Bands: 1
Origin
110.5,-4.5
Pixel Size
0.001,-0.001
No Data Value
*NoDataValue not set* 
Data Type
Int16 - Sixteen bit signed integer 
Pyramid overviews
Layer Spatial Reference System
+proj=longlat +datum=WGS84 +no_defs
Layer Extent (layer original source projection)
110.5000000000000000,-9.0000000000000000 : 117.0000000000000000,-4.5000000000000000
Band
Band 1
Band No
1
No Stats
No stats collected yet 

how to make geotiff format with python GDAL?

Answer 1

I fixed some minor issues and assumed some value parameters to test your code. I found out that this extrange issue was due to the absence of the minus sign in the last parameter of 'SetGeoTransform' method (-cell_size).

from osgeo import gdal, osr
import numpy as np

raster_classified = 'c:/Users/Usuario/pyqgis_data/raster_classified.tif'

col = 20 
row = 20

cell_size = 0.003
origin_x = 10000
origin_y = 10000

driver = gdal.GetDriverByName('GTiff')

outRaster = driver.Create(raster_classified, col, row, 1, gdal.GDT_Int16)

outband = outRaster.GetRasterBand(1)

outRaster.SetGeoTransform((origin_x, 
                           cell_size, 
                           0, 
                           origin_y  - (cell_size * row), 
                           0, 
                           -cell_size))

values = [ [] for i in range(row) ]

for i in range(row):
    for j in range(col):
            values[i].append(1)

outras_array = np.array(values)

outband.WriteArray(outras_array)
outRasterSRS = osr.SpatialReference()
outRasterSRS.ImportFromEPSG(4326)
outRaster.SetProjection(outRasterSRS.ExportToWkt())
outRaster = None

After running it at the Python Console of QGIS, I got a 20x20 *.tif raster (all pixels equal 1); as it can be seen at next image:

It worked.