Added utils_nb

utils_nb.py

@@ -0,0 +1,51 @@
+import os
+import socket
+from pyrocko import util
+
+op = os.path
+
+DATA_DIR = op.join(op.dirname(op.abspath(__file__)), 'data')
+os.makedirs(DATA_DIR, exist_ok=True)
+
+
+class NoInternetConnection(Exception):
+    pass
+
+
+def _download_data(fn, dldir=False):
+    fpath = data_file_path(fn)
+    if not op.exists(fpath):
+        if not have_internet():
+            raise NoInternetConnection(
+                'need internet access to download data')
+
+        url = 'http://data.pyrocko.org/examples/' + fn
+        print('downloading %s' % url)
+        if dldir:
+            util.download_dir(url, fpath)
+        else:
+            util.download_file(url, fpath)
+
+    return fpath
+
+
+def download_dir(fn):
+    return _download_data(fn, dldir=True)
+
+
+def download_file(fn):
+    return _download_data(fn)
+
+
+def data_file_path(fn):
+    return op.join(DATA_DIR, fn)
+
+
+def have_internet():
+    try:
+        return 0 < len([
+            (s.connect(('8.8.8.8', 80)), s.close())
+            for s in [socket.socket(socket.AF_INET, socket.SOCK_DGRAM)]])
+
+    except OSError:
+        return False