For iterating over lists, tuples, dictionaries, and strings, Python also includes a special keyword: in. You can use in very intuitively, like so:

for number in range(5):
  print number,

d = { 
  "name": "Eric",
  "age": 26
}

for key in d:
  print key, d[key],

for letter in "Eric":
  print letter,  # note the comma!

1. In the example above, first we create and iterate through a range, printing out 0 1 2 3 4. Note that the trailing comma ensures that we keep printing on the same line.
2. Next, we create a dictionary and iterate through, printing out age 26 name Eric. Dictionaries have no specific order.
3. Finally, we iterate through the letters of a string, printing out E r i c.