save project

a .py

+#  1n  3.14
+#  2n  6.28
+#  3n  9.42
+#  4n  12.56
+#  5n  15.7
+#  6n  18.84
+#  7n  21.98
+#  8n  25.12
+#  9n  28.26
+#  10n  31.4
+#  11n  34.54
+#  12n  37.68
+#  13n  40.82
+#  14n  43.96
+#  15n  47.1
+#  16n  50.24
+#  17n  53.38
+#  18n  56.52
+#  19n  59.66
+#  20n  62.8
+#  21n  65.94
+#  22n  69.08
+#  23n  
+#  24n  
+#  25n  
+#  26n  
+#  27n  
+#  28n  
+#  29n  
+#  30n  
+#  31n  
+#  32n  
+#  33n  
+#  34n  
+#  35n  
+#  36n  
+#  37n  
+#  38n  
+#  39n  
+#  40n  
\ No newline at end of file

my_tree.py

@@ -11,5 +11,17 @@ pen.left(90)
 pen.up()
 pen.backward(150)    # 后退
 pen.down()
-
+def tree():
+    if n >= 50:
+        pen.forward(n)
+        pen.right(30)
+        pen.forward(n/2)
+        pen.up()
+        pen.backward(n/2)
+        pen.down()
+        pen.left(30)
+        pen.forward(n/2)
+        pen.up
+        pen.backward(n)
+        pen.down()
 turtle.done()