Convert to Python 3.

This was converted using 2to3 from Python 3.7.

README.rst

@@ -112,7 +112,7 @@ Requirements
 Python Implementation
 ~~~~~~~~~~~~~~~~~~~~~
 
-- Python 2.7
+- Python 3.7
 
 C++ Implementation
 ~~~~~~~~~~~~~~~~~~

commands_to_compilation_database_py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """A program to generate a compilation database by parsing build
 commands on standard input or an input file.  It assumes that a single
 line compiles a single source file and the clang compiler is used as
@@ -107,7 +107,7 @@ if __name__ == '__main__':
             compile_command_regex = re.compile(r'^"([^"]+)" .+ "([^"]+)"$')
     else:
         if args.build_tool != '':
-            print 'warning: regex overriding build tool option.'
+            print('warning: regex overriding build tool option.')
 
         compile_command_regex = re.compile(args.compile_command_regex)
 

compare_compilation_databases_py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """A program to generate a compilation database by parsing build
 commands on standard input or an input file.  It assumes that a single
 line compiles a single source file and the clang compiler is used as
@@ -75,10 +75,10 @@ if __name__ == '__main__':
     f1 = args.filenames[1]
 
     if not os.path.exists(f0):
-        print "error: " + f0 + " does not exist."
+        print(("error: " + f0 + " does not exist."))
         sys.exit(1)
     if not os.path.exists(f1):
-        print "error: " + f1 + " does not exist."
+        print(("error: " + f1 + " does not exist."))
         sys.exit(1)
 
     compilation_map0 = {}
@@ -102,12 +102,12 @@ if __name__ == '__main__':
     keys1 = sorted(compilation_map1.keys())
 
     if len(keys0) != len(keys1):
-        print "error: compilation databases have different sizes: (%s, %s)." % (len(keys0), len(keys1))
+        print(("error: compilation databases have different sizes: (%s, %s)." % (len(keys0), len(keys1))))
         sys.exit(1)
     if keys0 != keys1:
-        print "error: compilation databases have different keys: (%s, %s)." % (keys0, keys1)
+        print(("error: compilation databases have different keys: (%s, %s)." % (keys0, keys1)))
         sys.exit(1)
     for k in keys0:
         if compilation_map0[k] != compilation_map1[k]:
-            print "error: compilation database is different for key %s: (%s, %s)." % (k, compilation_map0[k], compilation_map1[k])
+            print(("error: compilation database is different for key %s: (%s, %s)." % (k, compilation_map0[k], compilation_map1[k])))
             sys.exit(1)

files_to_compilation_database_py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """A program to generate a compilation database given a list of files,
 one per line.