Updated generator and parser to support Python 3.

modules/python/src2/gen2.py

 #!/usr/bin/env python
 
-import hdr_parser, sys, re, os, cStringIO
+from __future__ import print_function
+import hdr_parser, sys, re, os
 from string import Template
 
+if sys.version_info[0] >= 3:
+    from io import StringIO
+else:
+    from cStringIO import StringIO
+
 ignored_arg_types = ["RNG*"]
 
 gen_template_check_self = Template("""    if(!PyObject_TypeCheck(self, &pyopencv_${name}_Type))
@@ -33,6 +39,13 @@ gen_template_func_body = Template("""$code_decl
     }
 """)
 
+py_major_version = sys.version_info[0]
+if py_major_version >= 3:
+    head_init_str = "PyVarObject_HEAD_INIT(&PyType_Type, 0)"
+else:
+    head_init_str = """PyObject_HEAD_INIT(&PyType_Type)
+0,"""
+
 gen_template_simple_type_decl = Template("""
 struct pyopencv_${name}_t
 {
@@ -42,8 +55,7 @@ struct pyopencv_${name}_t
 
 static PyTypeObject pyopencv_${name}_Type =
 {
-    PyObject_HEAD_INIT(&PyType_Type)
-    0,
+    %s
     MODULESTR".$wname",
     sizeof(pyopencv_${name}_t),
 };
@@ -66,13 +78,13 @@ template<> bool pyopencv_to(PyObject* src, ${cname}& dst, const char* name)
         return true;
     if(!PyObject_TypeCheck(src, &pyopencv_${name}_Type))
     {
-        failmsg("Expected ${cname} for argument '%s'", name);
+        failmsg("Expected ${cname} for argument '%%s'", name);
         return false;
     }
     dst = ((pyopencv_${name}_t*)src)->v;
     return true;
 }
-""")
+""" % head_init_str)
 
 
 gen_template_type_decl = Template("""
@@ -84,8 +96,7 @@ struct pyopencv_${name}_t
 
 static PyTypeObject pyopencv_${name}_Type =
 {
-    PyObject_HEAD_INIT(&PyType_Type)
-    0,
+    %s
     MODULESTR".$wname",
     sizeof(pyopencv_${name}_t),
 };
@@ -110,14 +121,14 @@ template<> bool pyopencv_to(PyObject* src, Ptr<${cname}>& dst, const char* name)
         return true;
     if(!PyObject_TypeCheck(src, &pyopencv_${name}_Type))
     {
-        failmsg("Expected ${cname} for argument '%s'", name);
+        failmsg("Expected ${cname} for argument '%%s'", name);
         return false;
     }
     dst = ((pyopencv_${name}_t*)src)->v;
     return true;
 }
 
-""")
+""" % head_init_str)
 
 gen_template_map_type_cvt = Template("""
 template<> bool pyopencv_to(PyObject* src, ${cname}& dst, const char* name);
@@ -245,9 +256,9 @@ class ClassInfo(object):
         if decl:
             self.bases = decl[1].split()[1:]
             if len(self.bases) > 1:
-                print "Note: Class %s has more than 1 base class (not supported by Python C extensions)" % (self.name,)
-                print "      Bases: ", " ".join(self.bases)
-                print "      Only the first base class will be used"
+                print("Note: Class %s has more than 1 base class (not supported by Python C extensions)" % (self.name,))
+                print("      Bases: ", " ".join(self.bases))
+                print("      Only the first base class will be used")
                 self.bases = [self.bases[0].strip(",")]
                 #return sys.exit(-1)
             if self.bases and self.bases[0].startswith("cv::"):
@@ -280,8 +291,8 @@ class ClassInfo(object):
         if self.ismap:
             return self.gen_map_code(all_classes)
 
-        getset_code = cStringIO.StringIO()
-        getset_inits = cStringIO.StringIO()
+        getset_code = StringIO()
+        getset_inits = StringIO()
 
         sorted_props = [(p.name, p) for p in self.props]
         sorted_props.sort()
@@ -304,10 +315,10 @@ class ClassInfo(object):
                     getset_code.write(gen_template_set_prop.substitute(name=self.name, member=pname, membertype=p.tp, access=access_op))
                 getset_inits.write(gen_template_rw_prop_init.substitute(name=self.name, member=pname))
 
-        methods_code = cStringIO.StringIO()
-        methods_inits = cStringIO.StringIO()
+        methods_code = StringIO()
+        methods_inits = StringIO()
 
-        sorted_methods = self.methods.items()
+        sorted_methods = list(self.methods.items())
         sorted_methods.sort()
 
         for mname, m in sorted_methods:
@@ -315,7 +326,7 @@ class ClassInfo(object):
             methods_inits.write(m.get_tab_entry())
 
         baseptr = "NULL"
-        if self.bases and all_classes.has_key(self.bases[0]):
+        if self.bases and self.bases[0] in all_classes:
             baseptr = "&pyopencv_" + all_classes[self.bases[0]].name + "_Type"
 
         code = gen_template_type_impl.substitute(name=self.name, wname=self.wname, cname=self.cname,
@@ -609,7 +620,7 @@ class FuncInfo(object):
                         defval0 = "0"
                         tp1 = tp.replace("*", "_ptr")
                 if tp1.endswith("*"):
-                    print "Error: type with star: a.tp=%s, tp=%s, tp1=%s" % (a.tp, tp, tp1)
+                    print("Error: type with star: a.tp=%s, tp=%s, tp1=%s" % (a.tp, tp, tp1))
                     sys.exit(-1)
 
                 amapping = simple_argtype_mapping.get(tp, (tp, "O", defval0))
@@ -715,11 +726,11 @@ class PythonWrapperGenerator(object):
         self.classes = {}
         self.funcs = {}
         self.consts = {}
-        self.code_types = cStringIO.StringIO()
-        self.code_funcs = cStringIO.StringIO()
-        self.code_func_tab = cStringIO.StringIO()
-        self.code_type_reg = cStringIO.StringIO()
-        self.code_const_reg = cStringIO.StringIO()
+        self.code_types = StringIO()
+        self.code_funcs = StringIO()
+        self.code_func_tab = StringIO()
+        self.code_type_reg = StringIO()
+        self.code_const_reg = StringIO()
         self.class_idx = 0
 
     def add_class(self, stype, name, decl):
@@ -727,9 +738,9 @@ class PythonWrapperGenerator(object):
         classinfo.decl_idx = self.class_idx
         self.class_idx += 1
 
-        if self.classes.has_key(classinfo.name):
-            print "Generator error: class %s (cname=%s) already exists" \
-                % (classinfo.name, classinfo.cname)
+        if classinfo.name in self.classes:
+            print("Generator error: class %s (cname=%s) already exists" \
+                % (classinfo.name, classinfo.cname))
             sys.exit(-1)
         self.classes[classinfo.name] = classinfo
         if classinfo.bases and not classinfo.isalgorithm:
@@ -738,9 +749,9 @@ class PythonWrapperGenerator(object):
     def add_const(self, name, decl):
         constinfo = ConstInfo(name, decl[1])
 
-        if self.consts.has_key(constinfo.name):
-            print "Generator error: constant %s (cname=%s) already exists" \
-                % (constinfo.name, constinfo.cname)
+        if constinfo.name in self.consts:
+            print("Generator error: constant %s (cname=%s) already exists" \
+                % (constinfo.name, constinfo.cname))
             sys.exit(-1)
         self.consts[constinfo.name] = constinfo
 
@@ -779,7 +790,7 @@ class PythonWrapperGenerator(object):
         else:
             classinfo = self.classes.get(classname, ClassInfo(""))
             if not classinfo.name:
-                print "Generator error: the class for method %s is missing" % (name,)
+                print("Generator error: the class for method %s is missing" % (name,))
                 sys.exit(-1)
             func_map = classinfo.methods
 
@@ -819,7 +830,7 @@ class PythonWrapperGenerator(object):
                     self.add_func(decl)
 
         # step 2: generate code for the classes and their methods
-        classlist = self.classes.items()
+        classlist = list(self.classes.items())
         classlist.sort()
         for name, classinfo in classlist:
             if classinfo.ismap:
@@ -844,7 +855,7 @@ class PythonWrapperGenerator(object):
                 self.code_type_reg.write("MKTYPE2(%s);\n" % (classinfo.name,) )
 
         # step 3: generate the code for all the global functions
-        funclist = self.funcs.items()
+        funclist = list(self.funcs.items())
         funclist.sort()
         for name, func in funclist:
             code = func.gen_code(self.classes)
@@ -852,7 +863,7 @@ class PythonWrapperGenerator(object):
             self.code_func_tab.write(func.get_tab_entry())
 
         # step 4: generate the code for constants
-        constlist = self.consts.items()
+        constlist = list(self.consts.items())
         constlist.sort()
         for name, constinfo in constlist:
             self.gen_const_reg(constinfo)

modules/python/src2/hdr_parser.py

 #!/usr/bin/env python
 
+from __future__ import print_function
 import os, sys, re, string
 
 # the list only for debugging. The real list, used in the real OpenCV build, is specified in CMakeLists.txt
@@ -43,13 +44,13 @@ class CppHeaderParser(object):
     def get_macro_arg(self, arg_str, npos):
         npos2 = npos3 = arg_str.find("(", npos)
         if npos2 < 0:
-            print "Error: no arguments for the macro at %d" % (self.lineno,)
+            print("Error: no arguments for the macro at %d" % (self.lineno,))
             sys.exit(-1)
         balance = 1
         while 1:
             t, npos3 = self.find_next_token(arg_str, ['(', ')'], npos3+1)
             if npos3 < 0:
-                print "Error: no matching ')' in the macro call at %d" % (self.lineno,)
+                print("Error: no matching ')' in the macro call at %d" % (self.lineno,))
                 sys.exit(-1)
             if t == '(':
                 balance += 1
@@ -143,13 +144,13 @@ class CppHeaderParser(object):
                 angle_stack.append(0)
             elif w == "," or w == '>':
                 if not angle_stack:
-                    print "Error at %d: argument contains ',' or '>' not within template arguments" % (self.lineno,)
+                    print("Error at %d: argument contains ',' or '>' not within template arguments" % (self.lineno,))
                     sys.exit(-1)
                 if w == ",":
                     arg_type += "_and_"
                 elif w == ">":
                     if angle_stack[0] == 0:
-                        print "Error at %s:%d: template has no arguments" % (self.hname, self.lineno)
+                        print("Error at %s:%d: template has no arguments" % (self.hname, self.lineno))
                         sys.exit(-1)
                     if angle_stack[0] > 1:
                         arg_type += "_end_"
@@ -173,7 +174,7 @@ class CppHeaderParser(object):
             p1 = arg_name.find("[")
             p2 = arg_name.find("]",p1+1)
             if p2 < 0:
-                print "Error at %d: no closing ]" % (self.lineno,)
+                print("Error at %d: no closing ]" % (self.lineno,))
                 sys.exit(-1)
             counter_str = arg_name[p1+1:p2].strip()
             if counter_str == "":
@@ -358,7 +359,7 @@ class CppHeaderParser(object):
         if bool(re.match(r".*\)\s*const(\s*=\s*0)?", decl_str)):
             decl[2].append("/C")
         if "virtual" in decl_str:
-            print decl_str
+            print(decl_str)
         return decl
 
     def parse_func_decl(self, decl_str):
@@ -412,12 +413,12 @@ class CppHeaderParser(object):
         if decl_str.startswith("CVAPI"):
             rtype_end = decl_str.find(")", args_begin+1)
             if rtype_end < 0:
-                print "Error at %d. no terminating ) in CVAPI() macro: %s" % (self.lineno, decl_str)
+                print("Error at %d. no terminating ) in CVAPI() macro: %s" % (self.lineno, decl_str))
                 sys.exit(-1)
             decl_str = decl_str[args_begin+1:rtype_end] + " " + decl_str[rtype_end+1:]
             args_begin = decl_str.find("(")
         if args_begin < 0:
-            print "Error at %d: no args in '%s'" % (self.lineno, decl_str)
+            print("Error at %d: no args in '%s'" % (self.lineno, decl_str))
             sys.exit(-1)
 
         decl_start = decl_str[:args_begin].strip()
@@ -425,7 +426,7 @@ class CppHeaderParser(object):
         if decl_start.endswith("operator"):
             args_begin = decl_str.find("(", args_begin+1)
             if args_begin < 0:
-                print "Error at %d: no args in '%s'" % (self.lineno, decl_str)
+                print("Error at %d: no args in '%s'" % (self.lineno, decl_str))
                 sys.exit(-1)
             decl_start = decl_str[:args_begin].strip()
             # TODO: normalize all type of operators
@@ -455,7 +456,7 @@ class CppHeaderParser(object):
                     return [] # exotic - dynamic 2d array
                 else:
                     #print rettype, funcname, modlist, argno
-                    print "Error at %s:%d the function/method name is missing: '%s'" % (self.hname, self.lineno, decl_start)
+                    print("Error at %s:%d the function/method name is missing: '%s'" % (self.hname, self.lineno, decl_start))
                     sys.exit(-1)
 
         if self.wrap_mode and (("::" in funcname) or funcname.startswith("~")):
@@ -486,9 +487,9 @@ class CppHeaderParser(object):
             npos += 1
             t, npos = self.find_next_token(decl_str, ["(", ")", ",", "<", ">"], npos)
             if not t:
-                print "Error: no closing ')' at %d" % (self.lineno,)
-                print decl_str
-                print decl_str[arg_start:]
+                print("Error: no closing ')' at %d" % (self.lineno,))
+                print(decl_str)
+                print(decl_str[arg_start:])
                 sys.exit(-1)
             if t == "<":
                 angle_balance += 1
@@ -583,7 +584,7 @@ class CppHeaderParser(object):
             if block_type in ["file", "enum"]:
                 continue
             if block_type not in ["struct", "class", "namespace"]:
-                print "Error at %d: there are non-valid entries in the current block stack " % (self.lineno, self.block_stack)
+                print("Error at %d: there are non-valid entries in the current block stack " % (self.lineno, self.block_stack))
                 sys.exit(-1)
             if block_name:
                 n += block_name + "."
@@ -605,7 +606,7 @@ class CppHeaderParser(object):
             stmt_type = "block"
 
         if context == "block":
-            print "Error at %d: should not call parse_stmt inside blocks" % (self.lineno,)
+            print("Error at %d: should not call parse_stmt inside blocks" % (self.lineno,))
             sys.exit(-1)
 
         if context == "class" or context == "struct":
@@ -632,7 +633,7 @@ class CppHeaderParser(object):
                 try:
                     classname, bases, modlist = self.parse_class_decl(stmt[len("typedef "):])
                 except:
-                    print "Error at %s:%d" % (self.hname, self.lineno)
+                    print("Error at %s:%d" % (self.hname, self.lineno))
                     exit(1)
                 if classname.startswith("_Ipl"):
                     classname = classname[1:]
@@ -647,7 +648,7 @@ class CppHeaderParser(object):
                     try:
                         classname, bases, modlist = self.parse_class_decl(stmt)
                     except:
-                        print "Error at %s:%d" % (self.hname, self.lineno)
+                        print("Error at %s:%d" % (self.hname, self.lineno))
                         exit(1)
                     decl = []
                     if ("CV_EXPORTS_W" in stmt) or ("CV_EXPORTS_AS" in stmt) or (not self.wrap_mode):# and ("CV_EXPORTS" in stmt)):
@@ -767,7 +768,7 @@ class CppHeaderParser(object):
                 state = SCAN
 
             if state != SCAN:
-                print "Error at %d: invlid state = %d" % (self.lineno, state)
+                print("Error at %d: invlid state = %d" % (self.lineno, state))
                 sys.exit(-1)
 
             while 1:
@@ -795,7 +796,7 @@ class CppHeaderParser(object):
                     while 1:
                         t2, pos2 = self.find_next_token(l, ["\\", "\""], pos2)
                         if t2 == "":
-                            print "Error at %d: no terminating '\"'" % (self.lineno,)
+                            print("Error at %d: no terminating '\"'" % (self.lineno,))
                             sys.exit(-1)
                         if t2 == "\"":
                             break
@@ -836,7 +837,7 @@ class CppHeaderParser(object):
 
                 if token == "}":
                     if not self.block_stack:
-                        print "Error at %d: the block stack is empty" % (self.lineno,)
+                        print("Error at %d: the block stack is empty" % (self.lineno,))
                     self.block_stack[-1:] = []
                     if pos+1 < len(l) and l[pos+1] == ';':
                         pos += 1
@@ -851,13 +852,13 @@ class CppHeaderParser(object):
         Prints the list of declarations, retrieived by the parse() method
         """
         for d in decls:
-            print d[0], d[1], ";".join(d[2])
+            print(d[0], d[1], ";".join(d[2]))
             for a in d[3]:
-                print "   ", a[0], a[1], a[2],
+                print("   ", a[0], a[1], a[2], end="")
                 if a[3]:
-                    print "; ".join(a[3])
+                    print("; ".join(a[3]))
                 else:
-                    print
+                    print()
 
 if __name__ == '__main__':
     parser = CppHeaderParser()
@@ -867,4 +868,4 @@ if __name__ == '__main__':
     #for hname in sys.argv[1:]:
         #decls += parser.parse(hname, wmode=False)
     parser.print_decls(decls)
-    print len(decls)
+    print(len(decls))