Add __iter__ method to HDF5File class

bob/io/base/__init__.py

@@ -39,6 +39,9 @@ class HDF5File(HDF5File_C):
     """
     return self.has_key(x)
 
+  def __iter__(self):
+    return iter(self.keys())
+
 
 def _is_string(s):
   """Returns ``True`` if the given object is a string

bob/io/base/test_hdf5.py

@@ -480,6 +480,7 @@ def test_copy_constructor():
     assert "/Test/Data" in shallow
     assert hdf5.filename == shallow.filename
     assert hdf5.keys() == shallow.keys()
+    assert [key for key in hdf5] == shallow.keys()
     assert hdf5.cwd == shallow.cwd
 
     assert not deep.has_group("/Test")

doc/guide.rst

@@ -257,6 +257,27 @@ the variable `my_array` as an arrayset using
 :py:meth:`bob.io.base.HDF5File.read`. In this case, each position readout
 would return a 1D uint8 array instead of a 2D array.
 
+
+Pythonic operations on HDF5 files
+---------------------------------
+
+You can use some Pythonic opertations on :py:class:`bob.io.base.HDF5File`.
+You can iterate over :py:class:`bob.io.base.HDF5File` objects to get an
+iterable of keys instead of calling
+:py:meth:`bob.io.base.HDF5File.keys`. You can also use the ``in`` keyword
+instead of calling :py:meth:`bob.io.base.HDF5File.has_key`. For example:
+
+.. doctest::
+
+  >>> keys = f.keys() # Get a list of keys
+  >>> keys == [key for key in f] # instead you can also iterate over keys
+  True
+  >>> f.has_key('arrayset')
+  True
+  >>> 'arrayset' in f # you can use the `in` operator instead of `has_key`
+  True
+
+
 Array interfaces
 ----------------