Remove redundant code for EOL Python <= 3.6

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### Description
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There's a few bits and pieces of code to support Python <= 3.6 which are no longer needed and can be removed, to slightly simplify the codebase.

### Checklist
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This pull request is:

- [ ] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [x] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

**Have a nice day!**

Closes: #7544
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7544
Pull-request-sha: 282b4a91282902a57807aa2541b75b272b547127

Change-Id: I9ddf15fcf72551d52e3f027f337c7fee4aa9083b

1 files changed, 4 insertions, 10 deletions

diff --git a/examples/space_invaders/space_invaders.py b/examples/space_invaders/space_invaders.py
index 1690145db..bc97d62e2 100644
--- a/examples/space_invaders/space_invaders.py
+++ b/examples/space_invaders/space_invaders.py
@@ -2,7 +2,6 @@ import curses
 import logging
 import random
 import re
-import sys
 import textwrap
 import time
 
@@ -20,11 +19,6 @@ from sqlalchemy.orm import relationship
 from sqlalchemy.orm import Session
 
 
-_PY3 = sys.version_info > (3, 0)
-if _PY3:
-    xrange = range
-
-
 logging.basicConfig(
     filename="space_invaders.log",
     format="%(asctime)s,%(msecs)03d %(levelname)-5.5s %(message)s",
@@ -158,7 +152,7 @@ class GlyphCoordinate(Base):
         glyph = self.glyph
         data = glyph.glyph_for_state(self, state)
         for color, char in [
-            (data[i], data[i + 1]) for i in xrange(0, len(data), 2)
+            (data[i], data[i + 1]) for i in range(0, len(data), 2)
         ]:
 
             x = self.x + col
@@ -190,7 +184,7 @@ class GlyphCoordinate(Base):
         glyph = self.glyph
         x = min(max(self.x, 0), MAX_X)
         width = min(glyph.width, MAX_X - x) or 1
-        for y_a in xrange(self.y, self.y + glyph.height):
+        for y_a in range(self.y, self.y + glyph.height):
             y = y_a
             window.addstr(y + VERT_PADDING, x + HORIZ_PADDING, " " * width)
 
@@ -455,9 +449,9 @@ def init_positions(session):
         ("enemy1", 10),
     )
     for (ship_vert, (etype, score)) in zip(
-        xrange(5, 30, ENEMY_VERT_SPACING), arrangement
+        range(5, 30, ENEMY_VERT_SPACING), arrangement
     ):
-        for ship_horiz in xrange(0, 50, 10):
+        for ship_horiz in range(0, 50, 10):
             session.add(
                 GlyphCoordinate(
                     session, etype, ship_horiz, ship_vert, score=score