Looping through all raster cell values using GDAL via Python?

I'm trying to identify null/0 values in each of my raster bands. How can I loop through all the values of each band? I've tried this code, straight from the gdal/python cookbook website but this just gives stats for each band as a whole and for some reason it actually doesn't print a minimum value of 0 even though my raster does have 0 values, it shows a minimum value of 1.

I want to print every single cell value. Is there a way to do this?

from osgeo import gdal
import sys


src_ds = gdal.Open( "INPUT.tif" )

print "[ RASTER BAND COUNT ]: ", src_ds.RasterCount
for band in range( src_ds.RasterCount ):
    band += 1
    print "[ GETTING BAND ]: ", band
    srcband = src_ds.GetRasterBand(band)

    stats = srcband.GetStatistics( True, True )


    print "[ STATS ] =  Minimum=%.3f, Maximum=%.3f, Mean=%.3f, StdDev=%.3f" % ( \
            stats[0], stats[1], stats[2], stats[3] )

Answer

You may read it as array, using numpy:

from osgeo import gdal
import sys
import numpy as np

src_ds = gdal.Open( "INPUT.tif" )


print "[ RASTER BAND COUNT ]: ", src_ds.RasterCount
for band in range( src_ds.RasterCount ):
    band += 1
    print "[ GETTING BAND ]: ", band
    srcband = src_ds.GetRasterBand(band)

    stats = srcband.GetStatistics( True, True )

    print "[ STATS ] =  Minimum=%.3f, Maximum=%.3f, Mean=%.3f, StdDev=%.3f" % ( \
            stats[0], stats[1], stats[2], stats[3] )


    rast_array = np.array(src_ds.GetRasterBand(1).ReadAsArray())
    print rast_array

Using a sample raster, the above code will return:

[ RASTER BAND COUNT ]:  1
[ GETTING BAND ]:  1
[ STATS ] =  Minimum=1683.000, Maximum=1900.000, Mean=1820.854, StdDev=59.329
[[1900 1900 1898 1895 1892 1887 1879 1871 1863 1852 1845 1837 1824 1802
  1743 1725 1713 1705 1699 1693 1687 1683]

 [1897 1896 1894 1892 1890 1884 1877 1869 1862 1854 1847 1838 1820 1800
  1745 1729 1719 1712 1706 1701 1696 1695]
 [1892 1891 1890 1888 1885 1881 1875 1868 1861 1855 1849 1837 1817 1794
  1747 1732 1725 1720 1714 1710 1707 1706]
 [1887 1885 1884 1882 1880 1878 1873 1867 1860 1855 1849 1833 1815 1789
  1749 1738 1732 1728 1723 1720 1718 1715]
 [1882 1880 1878 1876 1875 1873 1871 1866 1861 1855 1849 1832 1817 1795
  1756 1744 1740 1737 1733 1730 1728 1725]
 [1880 1877 1874 1873 1870 1868 1867 1865 1860 1855 1850 1841 1834 1817
  1795 1769 1749 1746 1743 1740 1736 1731]

 [1880 1876 1873 1870 1869 1866 1863 1862 1859 1856 1852 1847 1843 1841
  1824 1812 1802 1775 1758 1747 1740 1733]
 [1879 1876 1873 1870 1869 1866 1863 1860 1858 1855 1852 1850 1847 1843
  1831 1819 1803 1782 1763 1747 1738 1730]
 [1879 1877 1874 1872 1869 1866 1864 1861 1858 1855 1852 1850 1850 1848
  1836 1816 1794 1775 1754 1744 1736 1728]
 [1880 1877 1875 1872 1869 1867 1864 1862 1858 1854 1850 1848 1850 1850
  1840 1806 1786 1767 1749 1742 1734 1726]
 [1881 1879 1876 1873 1870 1866 1864 1861 1857 1851 1843 1840 1841 1850
  1827 1797 1782 1769 1752 1742 1733 1723]

 [1882 1879 1876 1873 1870 1867 1864 1861 1855 1848 1839 1835 1833 1836
  1810 1794 1783 1771 1758 1747 1737 1729]
 [1882 1880 1876 1873 1869 1866 1862 1858 1854 1849 1838 1833 1826 1814
  1800 1792 1782 1773 1762 1752 1742 1733]
 [1881 1878 1874 1870 1867 1863 1860 1856 1853 1849 1840 1835 1821 1813
  1798 1790 1783 1774 1766 1757 1748 1738]]

(If you want to print each value separately, it could be easy to edit the code).