Make compliance.py Python 3 compatible

examples/ELASTIC/compliance.py

@@ -1,13 +1,14 @@
 #!/usr/bin/env python
 
 # This file reads in the file log.lammps generated by the script ELASTIC/in.elastic
-# It prints out the 6x6 tensor of elastic constants Cij 
+# It prints out the 6x6 tensor of elastic constants Cij
 # followed by the 6x6 tensor of compliance constants Sij
 # It uses the same conventions as described in:
-# Sprik, Impey and Klein PRB (1984).  
+# Sprik, Impey and Klein PRB (1984).
 # The units of Cij are whatever was used in log.lammps (usually GPa)
 # The units of Sij are the inverse of that (usually 1/GPa)
 
+from __future__ import print_function
 from numpy import zeros
 from numpy.linalg import inv
 
@@ -44,9 +45,8 @@ cindices[20] = (4,5)
 
 # open logfile
 
-logfile = open("log.lammps",'r')
-
-txt = logfile.read()
+with open("log.lammps",'r') as logfile:
+    txt = logfile.read()
 
 # search for 21 elastic constants
 
@@ -56,7 +56,7 @@ s2 = 0
 for ival in range(nvals):
     s1 = txt.find(valstr,s2)
     if (s1 == -1):
-        print "Failed to find elastic constants in log file"
+        print("Failed to find elastic constants in log file")
         exit(1)
     s1 += 1
     s2 = txt.find("\n",s1)
@@ -67,18 +67,18 @@ for ival in range(nvals):
     c[i1,i2] = float(words[valpos])
     c[i2,i1] = c[i1,i2]
 
-print "C tensor [GPa]"
+print("C tensor [GPa]")
 for i in range(6):
     for j in range(6):
-        print "%10.8g " % c[i][j],
-    print
-        
+        print("%10.8g " % c[i][j], end="")
+    print()
+
 # apply factor of 2 to columns of off-diagonal elements
 
 for i in range(6):
     for j in range(3,6):
         c[i][j] *= 2.0
-        
+
 s = inv(c)
 
 # apply factor of 1/2 to columns of off-diagonal elements
@@ -86,10 +86,9 @@ s = inv(c)
 for i in range(6):
     for j in range(3,6):
         s[i][j] *= 0.5
-        
-print "S tensor [1/GPa]"
+
+print("S tensor [1/GPa]")
 for i in range(6):
     for j in range(6):
-        print "%10.8g " % s[i][j],
-    print
-        
+        print("%10.8g " % s[i][j], end="")
+    print()