First read/write

docs/source/usage/firstread.rst

@@ -86,7 +86,7 @@ C++17
 .. code-block:: cpp
 
    auto series = io::Series(
-       "data%T.h5",
+       "data_%T.h5",
        io::Access::READ_ONLY);
 
 
@@ -96,9 +96,19 @@ Python
 .. code-block:: python3
 
    series = io.Series(
-       "data%T.h5",
+       "data_%T.h5",
        io.Access.read_only)
 
+.. tip::
+
+   Replace the file ending ``.h5`` with a wildcard ``.%E`` to let openPMD autodetect the ending from the file system.
+
+.. tip::
+
+   More detailed options can be passed via JSON or TOML as a further constructor parameter.
+   Try ``{"defer_iteration_parsing": true}`` to speed up the first access.
+   (Remember to explicitly ``it.open()`` iterations in that case.)
+
 Iteration
 ---------
 

docs/source/usage/firstwrite.rst

@@ -100,7 +100,7 @@ Python
 Iteration
 ---------
 
-Grouping by an arbitrary, positive integer number ``<N>`` in a series:
+Grouping by an arbitrary, nonnegative integer number ``<N>`` in a series:
 
 C++17
 ^^^^^