Add Nim Dictionaries

Nim-for-Python-Programmers.md

@@ -168,6 +168,17 @@ Use [Nim sequences](http://nim-lang.org/docs/tut1.html#advanced-types-sequences)
 
 Nim arrays and sequences can hold only items of the same type.
 
+### Python dictionaries
+
+``` Nim
+import tables
+
+var a = {"hallo": "World", "Key2": "Value2"}.newTable
+
+for key, value in a:
+  echo key, " " ,value
+```
+
 #### List Comprehensions
 ```
 import future  # required for the list comprehension syntactical sugar