Lecture 4: Lists, Tuples and Strings
=====================================

Based on the lecture and the readings (R&S Lists, Tuples & Strings)
you should be able to:

- Understand how to index a list, tuple, or string
- Understand how to construct a list in a loop
- Explain the difference between ``list1 = list2`` and ``list1 = list2[:]``

Below, please find some practice problems for this topic. These
problems should be completed by hand, that is, without the use of a
computer.

1. What is the output of the following code fragmemt?

.. code-block:: python

  lst = ['a', 'b', 'c', 'd', 'e']

  print(lst[0])
  print(lst[1])
  print(lst[-1])
  print(lst[:4])

2. Write an expression that will extract the substring ``"bcd"`` from ``s``:

.. code-block:: python

  s = 'abcde'


3. What will happen if I try to run the following code:

.. code-block:: python

  lst = [10, 20, 30]
  lst[3]


4. What is the output of the following code fragment?

.. code-block:: python

  x = ['abcde', [1, 2, 3, 4], 8, 9, 100, 'hello']
  y = x[0] + x[-1]
  z = x[0][:2]
  x.append(y)
  x.append(z)
  print(x)


5. What is the output of the following code fragment?

.. code-block:: python

  z = [0]*9
  z[2] = 98
  z[3] = 1
  z[8] = 4

  x = z[3]
  z[x] = 3
  z[z[8]] = 27

  print(z)

6. What is the output of the following code fragment?

.. code-block:: python

  lst = []
  for i in range(3,10):
      lst.append(i // 3)
  print(lst)