Address @paulromano comments in #1023

scripts/openmc-get-nndc-data

@@ -54,10 +54,7 @@ for f in files:
     req = urlopen(url)
 
     # Get file size from header
-    if sys.version_info[0] < 3:
-        file_size = int(req.info().getheaders('Content-Length')[0])
-    else:
-        file_size = req.length
+    file_size = req.length
     downloaded = 0
 
     # Check if file already downloaded

scripts/openmc-get-photon-data

@@ -12,8 +12,7 @@ import shutil
 import zipfile
 import argparse
 from io import BytesIO
-
-import requests
+from urllib.request import urlopen
 
 import openmc.data
 
@@ -32,6 +31,7 @@ args = parser.parse_args()
 
 base_url = 'http://www.nndc.bnl.gov/endf/b7.1/zips/'
 files = ['ENDF-B-VII.1-photoat.zip', 'ENDF-B-VII.1-atomic_relax.zip']
+block_size = 16384
 
 # ==============================================================================
 # DOWNLOAD FILES FROM NNDC SITE
@@ -39,13 +39,44 @@ files = ['ENDF-B-VII.1-photoat.zip', 'ENDF-B-VII.1-atomic_relax.zip']
 if not os.path.exists('photon_hdf5'):
     os.mkdir('photon_hdf5')
 
-
 for f in files:
     # Establish connection to URL
-    print('Downloading {}...'.format(f))
     url = base_url + f
-    r = requests.get(url, stream=True)
-    zipfile.ZipFile(BytesIO(r.content)).extractall()
+    req = urlopen(url)
+
+    # Get file size from header
+    file_size = req.length
+    downloaded = 0
+
+    # Check if file already downloaded
+    if os.path.exists(f):
+        if os.path.getsize(f) == file_size:
+            print('Skipping ' + f)
+            continue
+        else:
+            overwrite = input('Overwrite {}? ([y]/n) '.format(f))
+            if overwrite.lower().startswith('n'):
+                continue
+
+    # Copy file to disk
+    print('Downloading {}... '.format(f), end='')
+    with open(f, 'wb') as fh:
+        while True:
+            chunk = req.read(block_size)
+            if not chunk: break
+            fh.write(chunk)
+            downloaded += len(chunk)
+            status = '{0:10}  [{1:3.2f}%]'.format(
+                downloaded, downloaded * 100. / file_size)
+            print(status + chr(8)*len(status), end='')
+        print('')
+
+# ==============================================================================
+# EXTRACT FILES
+
+for f in files:
+    print('Extracting {0}...'.format(f))
+    zipfile.ZipFile(f).extractall()
 
 # ==============================================================================
 # GENERATE HDF5 DATA LIBRARY

scripts/openmc-make-compton

@@ -20,10 +20,7 @@ block_size = 16384
 req = urlopen(base_url + filename)
 
 # Get file size from header
-if sys.version_info[0] < 3:
-    file_size = int(req.info().getheaders('Content-Length')[0])
-else:
-    file_size = req.length
+file_size = req.length
 downloaded = 0
 
 # Check if file already downloaded