example of hdf5 via h5py

zingale · zingale · commit d4632b8a2191 · 2017-05-07T20:11:24.000-04:00
diff --git a/examples/h5py/h5_example.py b/examples/h5py/h5_example.py
@@ -0,0 +1,36 @@
+import numpy as np
+import h5py
+
+
+a = np.arange(1000, dtype=np.float64).reshape(25, 40)
+
+with h5py.File("test.h5", "w") as f:
+    
+    # attributes are meta-data that can help describe the data
+    # in h5py, they are dictionary keys
+    f.attrs["about"] = "a test HDF5 file with h5py"
+
+    # groups can be thought of as subdirectories in the output file,
+    # and can help you organize data together logically
+    grp = f.create_group("data")
+    
+    # a numpy array is a dataset in HDF5 -- it will figure out the
+    # dimensions and type from the array itself
+    grp.create_dataset("a", data=a)
+
+    # there can be attributes in the group too
+    grp.attrs["array info"] = "a simple array"
+
+
+# now we'll try to read it in
+with h5py.File("test.h5", "r") as f:
+
+    # access the group we stored our data in
+    g = f["data"]
+
+    aread = np.array(g["a"])
+
+
+# are they the same?
+da = a - aread
+print(np.max(abs(da)))
