'U' mode for file opening deprecated in Python 3

mulgrids.py

@@ -11,7 +11,7 @@
 You should have received a copy of the GNU Lesser General Public License along with PyTOUGH.  If not, see <http://www.gnu.org/licenses/>."""
 
 from __future__ import print_function
-
+import sys
 from string import ascii_lowercase, ascii_uppercase
 from geometry import *
 from fixed_format_file import *
@@ -1285,7 +1285,8 @@ def read_wells(self, geo):
     def read(self, filename):
         """Reads MULgraph grid from file"""
         self.empty()
-        geo = fixed_format_file(filename, 'rU',
+        mode = 'r' if sys.version_info > (3,) else 'rU'
+        geo = fixed_format_file(filename, mode,
                                 mulgrid_format_specification, self.read_function)
         self.read_header(geo)
         if self.type == 'GENER':
@@ -1558,7 +1559,8 @@ def from_gmsh(self, filename, layers, convention = 0, atmos_type = 2,
         specified layer structure."""
         grid = mulgrid(type = 'GENER', convention = convention, atmos_type = atmos_type)
         grid.empty()
-        gmsh = open(filename, 'rU')
+        mode = 'r' if sys.version_info > (3,) else 'rU'
+        gmsh = open(filename, mode)
         line = ''
         chars = uniqstring(chars)
         while not '$Nodes' in line: line = gmsh.readline()
@@ -3673,7 +3675,6 @@ def fit_columns(self, data, alpha = 0.1, beta = 0.1, columns = [],
         if grid_boundary: bounds = geo.boundary_polygon
         else: bounds = None
         qtree = geo.column_quadtree(columns)
-        import sys
         nd = len(data)
         for idata, d in enumerate(data):
             col = geo.column_containing_point(d[0:2], geo_columns,
@@ -4050,9 +4051,8 @@ def parse_layers(filename):
         def parse_segments(filename, bottom_layer):
             """Parse AMESH segment file and return list of 2-D segments, together
             with the minimum segment length."""
-            from sys import float_info
             segment_data = []
-            min_segment_length = float_info.max
+            min_segment_length = sys.float_info.max
             for line in open(filename):
                 x1, y1, x2, y2 = float(line[0: 15]), float(line[15: 30]), \
                                  float(line[30: 45]), float(line[45: 60])

t2data.py

@@ -11,7 +11,7 @@
 You should have received a copy of the GNU Lesser General Public License along with PyTOUGH.  If not, see <http://www.gnu.org/licenses/>."""
 
 from __future__ import print_function
-
+import sys
 from fixed_format_file import *
 from t2grids import *
 from t2incons import *
@@ -1521,7 +1521,8 @@ def read_extra_precision(self):
         from os.path import exists
         filename = self.extra_precision_filename
         if exists(filename):
-            xpfile = t2_extra_precision_data_parser(self.extra_precision_filename, 'rU',
+            mode = 'r' if sys.version_info > (3,) else 'rU'
+            xpfile = t2_extra_precision_data_parser(self.extra_precision_filename, mode,
                                                     read_function = self.read_function)
             read_fn = dict(zip(t2_extra_precision_sections,
                                [self.read_rocktypes, self.read_blocks, self.read_connections,
@@ -1566,7 +1567,8 @@ def read(self, filename = '', meshfilename = ''):
         an associated '.pdat' file, if it exists.
         """
         if filename: self.filename = filename
-        infile = t2data_parser(self.filename, 'rU', read_function = self.read_function)
+        mode = 'r' if sys.version_info > (3,) else 'rU'
+        infile = t2data_parser(self.filename, mode, read_function = self.read_function)
         self.read_title(infile)
         self._sections = []
         more = True
@@ -1591,7 +1593,8 @@ def read(self, filename = '', meshfilename = ''):
         if meshfilename and (self.grid.num_blocks == 0):
             self.meshfilename = meshfilename
             if isinstance(meshfilename, str):
-                meshfile = t2data_parser(self.meshfilename, 'rU', read_function = self.read_function)
+                mode = 'r' if sys.version_info > (3,) else 'rU'
+                meshfile = t2data_parser(self.meshfilename, mode, read_function = self.read_function)
                 self.read_meshfile(meshfile)
                 meshfile.close()
             elif isinstance(meshfilename, (list, tuple)):

t2incons.py

@@ -164,7 +164,8 @@ def delete_incon(self, block):
     def read(self, filename, num_variables = None):
         """Reads initial conditions from file."""
         self.empty()
-        infile = t2incon_parser(filename, 'rU', read_function = self.read_function)
+        mode = 'r' if sys.version_info > (3,) else 'rU'
+        infile = t2incon_parser(filename, mode, read_function = self.read_function)
         infile.readline() # skip header
         finished = False
         timing = False

t2listing.py

@@ -19,7 +19,7 @@
 from mulgrids import fix_blockname, valid_blockname
 from fixed_format_file import fortran_float, fortran_int
 import io
-from sys import version_info
+import sys
 
 class listingtable(object):
 
@@ -191,7 +191,7 @@ def __repr__(self): return self.title
     def close(self):
         self._file.close()
 
-    if version_info[0] < 3:
+    if sys.version_info < (3,):
         def readline(self):
             """Reads next line and returns it as a string. In Python 2.x,
             readline() already returns a string and doesn't need decoding.
@@ -1388,7 +1388,8 @@ def read(self, filename):
         files = glob(filename)
         configured = False
         for i, fname in enumerate(files):
-            self._file = open(fname,'rU')
+            mode = 'r' if sys.version_info > (3,) else 'rU'
+            self._file = open(fname, mode)
             header = self._file.readline()
             if header:
                 if not configured: