Differences

This shows you the differences between two versions of the page.

--- workshops:blender:python_basics [2015/06/20 23:09] – [Variables] Julien Deswaef
+++ workshops:blender:python_basics [2015/06/20 23:29] (current) – [Loops] Julien Deswaef
@@ Line 68: / Line 68: @@
 </code>
-==== Useful things ====
+===== Functions =====
+The keyword to define a function in Python is ''def''.
+<code=python>
+def sum(a, b):
+    return a + b
+sum(123, 456)
+# 579
+</code>
+It is possible to define default values for the parameters, with the same previous example
+<code=python>
+def sum(a, b=1):
+    return a + b
+sum(123)
+# 124
+</code>
+So in this case, since we are calling the function without a second parameter, Python will use the default value of that second one to execute the function. In this case, it will just add one.
+===== Loops =====
+Compared to Javascript, Java or C for example, loops are written in a different manner. Python uses iterators a lot for a lot of its datat types. So we don't use or don't have to create an "index variable" to loop over some content. We just need to use the iterator.
+<code=python>
+a = [ 10, 20, 30, 40 ]
+for elements in a:
+    print( elements )
+# 10
+# 20
+# 30
+# 40
+msg = "hello"
+for letter in msg:
+    print(letter)
+# h
+# e
+# l
+# l
+# o
+</code>
+If you really need to get an index, it's possible to construct it with the function ''enumerate()''
+<code=python>
+for index, letter in enumerate(msg):
+    print( str(index) + ": " + letter)
+# 0: h
+# 1: e
+# 2: l
+# 3: l
+# 4: o
+</code>
+===== Useful things =====
 === Commenting ===
 <code=python>