@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 # This is wrong on purpose to illustrate a point
 
 
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 # This is wrong on purpose to illustrate a point
 
 
@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+
+def do_twice(f, value):
+    f(value)
+    f(value)
+
+def print_twice(x):
+    print x * 2
+
+def do_four(f, value):
+    do_twice(f, value)
+    do_twice(f, value)
+
+print("Reult of do_twice: ")
+do_twice(print_twice, 'spam')
+
+print("Result of do_four: ")
+do_four(print_twice, 'spam')
@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+
+def print_boundary():
+    print '+ '+'- ' * 4 + '+ ' + '- ' * 4 + '+'
+   
+def print_slash():
+    print '/ '+'  ' * 4 + '/ ' + '  ' * 4 + '/ '
+
+def print_square():
+    print_boundary()
+    print_slash(), print_slash(), print_slash(), print_slash() 
+    print_boundary()
+    print_slash(), print_slash(), print_slash(), print_slash()
+    print_boundary()
+
+def print_boundary_2():
+    print '+ '+'- ' * 4 + '+ ' + '- ' * 4 + '+ ' +'- ' * 4 + '+ ' + '- ' * 4 + '+'
+         
+def print_slash_2():
+    print '/ '+'  ' * 4 + '/ ' + '  ' * 4 + '/ ' +'  ' * 4 + '/ ' + '  ' * 4 + '/ '
+
+def print_fourRows_fourColumns():
+    print_boundary_2()
+    print_slash_2(), print_slash_2(), print_slash_2(), print_slash_2()
+    print_boundary_2()
+    print_slash_2(), print_slash_2(), print_slash_2(), print_slash_2()
+    print_boundary_2()
+    print_slash_2(), print_slash_2(), print_slash_2(), print_slash_2()
+    print_boundary_2()
+
+if __name__ == "__main__":
+    print_square()
+    print "     "
+    print_fourRows_fourColumns()
+
+
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-#!/usr/bin/python`
	`1`	`+#!/usr/bin/env python`
`2`	`2`
`3`	`3`	`# This is wrong on purpose to illustrate a point`
`4`	`4`