return tuples, not lists from DatasetReader

rasterio/_base.pyx

@@ -282,11 +282,11 @@ cdef class DatasetReader(object):
 
     @property
     def indexes(self):
-        return list(range(1, self.count+1))
+        return tuple(range(1, self.count+1))
 
     @property
     def dtypes(self):
-        """Returns an ordered list of all band data types."""
+        """Returns an ordered tuple of all band data types."""
         cdef void *hband = NULL
         if not self._dtypes:
             if self._hds == NULL:
@@ -295,7 +295,7 @@ cdef class DatasetReader(object):
                 hband = _gdal.GDALGetRasterBand(self._hds, i+1)
                 self._dtypes.append(
                     dtypes.dtype_fwd[_gdal.GDALGetRasterDataType(hband)])
-        return self._dtypes
+        return tuple(self._dtypes)
     
     @property
     def block_shapes(self):
@@ -316,7 +316,7 @@ cdef class DatasetReader(object):
                     raise ValueError("Null band")
                 _gdal.GDALGetBlockSize(hband, &xsize, &ysize)
                 self._block_shapes.append((ysize, xsize))
-        return self._block_shapes
+        return tuple(self._block_shapes)
 
     def get_nodatavals(self):
         cdef void *hband = NULL
@@ -347,7 +347,7 @@ cdef class DatasetReader(object):
                 log.debug("Nodata value: %f", nodataval)
                 self._nodatavals.append(val)
 
-        return self._nodatavals
+        return tuple(self._nodatavals)
 
     property nodatavals:
         """Nodata values for each band."""

tests/test_blocks.py

@@ -69,7 +69,7 @@ class RasterBlocksTest(unittest.TestCase):
     def test_blocks(self):
         with rasterio.open('tests/data/RGB.byte.tif') as s:
             self.assertEqual(len(s.block_shapes), 3)
-            self.assertEqual(s.block_shapes, [(3, 791), (3, 791), (3, 791)])
+            self.assertEqual(s.block_shapes, ((3, 791), (3, 791), (3, 791)))
             windows = s.block_windows(1)
             (j,i), first = next(windows)
             self.assertEqual((j,i), (0, 0))

tests/test_nodata.py

@@ -15,7 +15,7 @@ def test_nodata(tmpdir):
             with rasterio.open(dst_path, 'w', **src.meta) as dst:
                 assert dst.nodata == 0.0
                 assert dst.meta['nodata'] == 0.0
-                assert dst.nodatavals == [0.0, 0.0, 0.0]
+                assert dst.nodatavals == (0.0, 0.0, 0.0)
     info = subprocess.check_output([
         'gdalinfo', dst_path])
     pattern = b'Band 1.*?NoData Value=0'
@@ -34,7 +34,7 @@ def test_set_nodata(tmpdir):
             with rasterio.open(dst_path, 'w', **meta) as dst:
                 assert dst.nodata == 42
                 assert dst.meta['nodata'] == 42
-                assert dst.nodatavals == [42, 42, 42]
+                assert dst.nodatavals == (42, 42, 42)
     info = subprocess.check_output([
         'gdalinfo', dst_path])
     pattern = b'Band 1.*?NoData Value=42'

tests/test_read.py

@@ -22,9 +22,9 @@ class ReaderContextTest(unittest.TestCase):
             self.assertEqual(s.width, 791)
             self.assertEqual(s.height, 718)
             self.assertEqual(s.shape, (718, 791))
-            self.assertEqual(s.dtypes, [rasterio.ubyte]*3)
-            self.assertEqual(s.nodatavals, [0]*3)
-            self.assertEqual(s.indexes, [1,2,3])
+            self.assertEqual(s.dtypes, tuple([rasterio.ubyte] * 3))
+            self.assertEqual(s.nodatavals, (0, 0, 0))
+            self.assertEqual(s.indexes, (1, 2, 3))
             self.assertEqual(s.crs['init'], 'epsg:32618')
             self.assert_(s.crs_wkt.startswith('PROJCS'), s.crs_wkt)
             for i, v in enumerate((101985.0, 2611485.0, 339315.0, 2826915.0)):
@@ -44,8 +44,8 @@ class ReaderContextTest(unittest.TestCase):
         self.assertEqual(s.width, 791)
         self.assertEqual(s.height, 718)
         self.assertEqual(s.shape, (718, 791))
-        self.assertEqual(s.dtypes, [rasterio.ubyte]*3)
-        self.assertEqual(s.nodatavals, [0]*3)
+        self.assertEqual(s.dtypes, tuple([rasterio.ubyte] * 3))
+        self.assertEqual(s.nodatavals, (0, 0, 0))
         self.assertEqual(s.crs['init'], 'epsg:32618')
         self.assertEqual(
             s.affine, 

tests/test_rio_convert.py

@@ -111,7 +111,7 @@ def test_dtype(tmpdir):
         ['tests/data/RGB.byte.tif', outputname, '--dtype', 'uint16'])
     assert result.exit_code == 0
     with rasterio.open(outputname) as src:
-        assert src.dtypes == ['uint16'] * 3
+        assert src.dtypes == tuple(['uint16'] * 3)
 
 
 def test_dtype_rescaling_uint8_full(tmpdir):

tests/test_update.py

@@ -58,7 +58,7 @@ def test_update_nodatavals(data):
     with rasterio.open(tiffname, 'r+') as f:
         f.nodata = 255
     with rasterio.open(tiffname) as f:
-        assert f.nodatavals == [255, 255, 255]
+        assert f.nodatavals == (255, 255, 255)
 
 
 def test_update_nodatavals_error(data):

tests/test_write.py

@@ -61,7 +61,7 @@ def test_context(tmpdir):
         assert s.width == 100
         assert s.height == 100
         assert s.shape == (100, 100)
-        assert s.indexes == [1]
+        assert s.indexes == (1,)
         assert repr(s) == "<open RasterUpdater name='%s' mode='w'>" % name
     assert s.closed == True
     assert s.count == 1
@@ -122,7 +122,7 @@ def test_write_float(tmpdir):
             name, 'w', 
             driver='GTiff', width=100, height=100, count=2,
             dtype=rasterio.float32) as s:
-        assert s.dtypes == [rasterio.float32]*2
+        assert s.dtypes == (rasterio.float32, rasterio.float32)
         s.write_band(1, a)
         s.write_band(2, a)
     info = subprocess.check_output(["gdalinfo", "-stats", name]).decode('utf-8')