Drop Python 2 support

Closes #179

README.rst

@@ -52,10 +52,4 @@ There are some other similar libraries, but astor focuses on the following areas
     Other derivatives of Armin's code are floating around, and typically
     have fixes for a few corner cases that happened to be noticed by the
     maintainers, but most of them have not been tested as thoroughly as
-    astor.  One exception may be the version of codegen
-    `maintained at github by CensoredUsername`__.  This has been tested
-    to work properly on Python 2.7 using astor's test suite, and, as it
-    is a single source file, it may be easier to drop into some applications
-    that do not require astor's other features or Python 3.x compatibility.
-
-__ https://github.com/CensoredUsername/codegen
+    astor.

astor/code_gen.py

@@ -149,8 +149,6 @@ class SourceGenerator(ExplicitNodeVisitor):
 
     """
 
-    using_unicode_literals = False
-
     def __init__(self, indent_with, add_line_information=False,
                  pretty_string=pretty_string,
                  # constants
@@ -321,10 +319,6 @@ def visit_ImportFrom(self, node):
         self.statement(node, 'from ', node.level * '.',
                        node.module or '', ' import ')
         self.comma_list(node.names)
-        # Goofy stuff for Python 2.7 _pyio module
-        if node.module == '__future__' and 'unicode_literals' in (
-                x.name for x in node.names):
-            self.using_unicode_literals = True
 
     def visit_Import(self, node):
         self.statement(node, 'import ')
@@ -455,15 +449,6 @@ def visit_NameConstant(self, node):
     def visit_Pass(self, node):
         self.statement(node, 'pass')
 
-    def visit_Print(self, node):
-        # XXX: python 2.6 only
-        self.statement(node, 'print ')
-        values = node.values
-        if node.dest is not None:
-            self.write(' >> ')
-            values = [node.dest] + node.values
-        self.comma_list(values, not node.nl)
-
     def visit_Delete(self, node):
         self.statement(node, 'del ')
         self.comma_list(node.targets)
@@ -540,14 +525,9 @@ def visit_Continue(self, node):
         self.statement(node, 'continue')
 
     def visit_Raise(self, node):
-        # XXX: Python 2.6 / 3.0 compatibility
         self.statement(node, 'raise')
         if self.conditional_write(' ', self.get_exc(node)):
             self.conditional_write(' from ', node.cause)
-        elif self.conditional_write(' ', self.get_type(node)):
-            set_precedence(node, node.inst)
-            self.conditional_write(', ', node.inst)
-            self.conditional_write(', ', node.tback)
 
     # Match statement (introduced in Python 3.10)
     def visit_Match(self, node):
@@ -742,14 +722,12 @@ def recurse(node):
             mystr = ''.join(result[index:])
             del result[index:]
             self.colinfo = res_index, str_index  # Put it back like we found it
-            uni_lit = False  # No formatted byte strings
 
         else:
             assert value is not None, "Node value cannot be None"
             mystr = value
-            uni_lit = self.using_unicode_literals
 
-        mystr = self.pretty_string(mystr, embedded, current_line, uni_lit)
+        mystr = self.pretty_string(mystr, embedded, current_line)
 
         if is_joined:
             mystr = 'f' + mystr
@@ -804,27 +782,10 @@ def part(p, imaginary):
             s = real
         self.write(s)
 
-    def visit_Num(self, node,
-                  # constants
-                  new=sys.version_info >= (3, 0)):
+    def visit_Num(self, node):
         with self.delimit(node) as delimiters:
             self._handle_numeric_constant(node.n)
 
-            # We can leave the delimiters handling in visit_Num
-            # since this is meant to handle a Python 2.x specific
-            # issue and ast.Constant exists only in 3.6+
-
-            # The Python 2.x compiler merges a unary minus
-            # with a number.  This is a premature optimization
-            # that we deal with here...
-            if not new and delimiters.discard:
-                if not isinstance(node.n, complex) and node.n < 0:
-                    pow_lhs = Precedence.Pow + 1
-                    delimiters.discard = delimiters.pp != pow_lhs
-                else:
-                    op = self.get__p_op(node)
-                    delimiters.discard = not isinstance(op, ast.USub)
-
     def visit_Tuple(self, node):
         with self.delimit(node) as delimiters:
             # Two things are special about tuples:
@@ -902,6 +863,7 @@ def visit_NamedExpr(self, node):
     def visit_UnaryOp(self, node):
         with self.delimit(node, node.op) as delimiters:
             set_precedence(delimiters.p, node.operand)
+            # TODO: Remove this.
             # In Python 2.x, a unary negative of a literal
             # number is merged into the number itself.  This
             # bit of ugliness means it is useful to know
@@ -989,11 +951,6 @@ def visit_IfExp(self, node):
     def visit_Starred(self, node):
         self.write('*', node.value)
 
-    def visit_Repr(self, node):
-        # XXX: python 2.6 only
-        with self.delimit('``'):
-            self.visit(node.value)
-
     def visit_Module(self, node):
         self.write(*node.body)
 

astor/file_util.py

@@ -13,13 +13,9 @@
 
 import ast
 import sys
+import tokenize
 import os
 
-try:
-    from tokenize import open as fopen
-except ImportError:
-    fopen = open
-
 
 class CodeToAst(object):
     """Given a module, or a function that was compiled as part
@@ -56,12 +52,9 @@ def parse_file(fname):
         """Parse a python file into an AST.
 
         This is a very thin wrapper around ast.parse
-
-            TODO: Handle encodings other than the default for Python 2
-                        (issue #26)
         """
         try:
-            with fopen(fname) as f:
+            with tokenize.open(fname) as f:
                 fstr = f.read()
         except IOError:
             if fname != 'stdin':

astor/string_repr.py

@@ -13,23 +13,10 @@
 
 This is a lot harder than you would think.
 
-This has lots of Python 2 / Python 3 ugliness.
-
 """
 
 import re
 
-try:
-    special_unicode = unicode
-except NameError:
-    class special_unicode(object):
-        pass
-
-try:
-    basestring = basestring
-except NameError:
-    basestring = str
-
 
 def _properly_indented(s, line_indent):
     mylist = s.split('\n')[1:]
@@ -61,8 +48,7 @@ def string_triplequote_repr(s):
     return '"""%s"""' % _prep_triple_quotes(s)
 
 
-def pretty_string(s, embedded, current_line, uni_lit=False,
-                  min_trip_str=20, max_line=100):
+def pretty_string(s, embedded, current_line, min_trip_str=20, max_line=100):
     """There are a lot of reasons why we might not want to or
        be able to return a triple-quoted string.  We can always
        punt back to the default normal string.
@@ -71,9 +57,9 @@ def pretty_string(s, embedded, current_line, uni_lit=False,
     default = repr(s)
 
     # Punt on abnormal strings
-    if (isinstance(s, special_unicode) or not isinstance(s, basestring)):
+    if isinstance(s, unicode):
         return default
-    if uni_lit and isinstance(s, bytes):
+    if isinstance(s, bytes):
         return 'b' + default
 
     len_s = len(default)

tests/test_code_gen.py

@@ -571,10 +571,9 @@ def test_deprecated_constant_nodes(self):
 
         self.assertAstEqualsSource(ast.Ellipsis(), "...")
 
-        if sys.version_info >= (3, 0):
-            self.assertAstEqualsSource(
-                ast.Assign(targets=[ast.Name(id='spam')], value=ast.Bytes(b"Bytes")),
-                "spam = b'Bytes'")
+        self.assertAstEqualsSource(
+            ast.Assign(targets=[ast.Name(id='spam')], value=ast.Bytes(b"Bytes")),
+            "spam = b'Bytes'")
 
         self.assertAstEqualsSource(
             ast.Assign(targets=[ast.Name(id='spam')], value=ast.Str("String")),

tests/test_misc.py

@@ -101,18 +101,5 @@ def test_auto_generated_attributes(self):
         self.assertEqual(treewalk.__dict__['post_handlers'], {})
 
 
-class SourceReprTestCase(unittest.TestCase):
-    """
-    Tests for helpers in astor.source_repr module.
-
-    Note that these APIs are not public.
-    """
-
-    @unittest.skipUnless(sys.version_info[0] == 2, 'only applies to Python 2')
-    def test_split_lines_unicode_support(self):
-        source = [u'copy', '\n']
-        self.assertEqual(split_lines(source), source)
-
-
 if __name__ == '__main__':
     unittest.main()