Lab # 7 More programming with lists

Starting Lab 7




    • Open a browser and log into Brightspace



    • On the left hand side under Labs tab, find lab6 material contained in lab7-students.pdf file



    • Download that file to the Desktop.




















2
Before starting, always make sure you are running Python 3



This slide is applicable to all labs, exercises, assignments … etc


ALWAYS MAKE SURE FIRST that you are running Python 3.4 (3.5/3.5 is fine too)


That is, when you click on IDLE (or start python any other way) look at the first line that the Python shell displays. It should say Python 3.4 or 3.5 or 3.6 (and then some extra digits)


If you do not know how to do this, read the material provided with Lab 1. It explains it step by step







3
Task (to be completed at home)


I strongly encourage you to complete these two quizes at home. Leave the time in the lab for questions to TAs about quiz problems whose solution you do not understand.


Go to coursera webpage and log in.

1.Go to the following link to and complete the Quiz of Week 4. You will find the quiz at the bottom of the page
https://www.coursera.org/learn/learn-to-program/home/week/4

2.Go to the following link to and complete the Quiz of Week 5. You will find the quiz at the bottom of the page

https://www.coursera.org/learn/learn-to-program/home/week/5


In Week 5 quiz you do not need to answer last couple of questions about “files” as we did not cover that (yet).

•  You can do each quiz more than once.
4
Programming Exercises (the most important lab)

The following exercises are easily the most important exercises in this whole semester. Solving these problems (by yourself preferably) should greatly increase your understanding of computational problem solving and programming.


Do as many as possible (preferably all) of the following 13 programming exercises from your 3rd recommended textbook by Perkovic. 11 of 13 are mandatory for this lab (your choice which 11) -- see the slides to come.


Introduction to Computing Using Python: An Application Development Focus, 2nd Edition, Ljubomir Perkovic


Sometimes the author uses a word “outputs”. By that he means “prints” First recall from the next 4 slides, list (and few string) functions and methods that you will need.
Introduction to Computing Using Python by Lj. Perkovic




List operators and functions



Like strings, lists can be manipulated with operators and functions





Usage
Explanation


x in lst
x is an item of lst
x not in lst
x is not an item of lst
lst + lstB
Concatenation of lst and lstB
lst*n, n*lst
Concatenation of n copies of lst
lst[i]
Item at index i of lst
len(lst)
Number of items in lst
min(lst)
Minimum item in lst
max(lst)
Maximum item in lst
sum(lst)
Sum of items in lst









    • lst = [1, 2, 3]

    • lstB = [0, 4]

    • 4 in lst

False

    • 4 not in lst True

    • lst + lstB [1, 2, 3, 0, 4]

    • 2*lst

[1, 2, 3, 1, 2, 3]

    • lst[0]

1

    • lst[1]

2

    • lst[-1]

3

    • len(lst)

3

    • min(lst)

1

    • max(lst)

3

    • sum(lst)

6

    • help(list

...
Introduction to Computing Using Python by Lj. Perkovic




Lists methods


Usage
Explanation


lst.append(item)
adds item to the end of lst


lst.count(item)
returns the number of times item

occurs in lst
lst.index(item)
Returns index of (first occurrence of)

item in lst
lst.pop()
Removes and returns the last item in lst
lst.remove(item)
Removes (the first occurrence of) item

from lst
lst.reverse(item)
Reverses the order of items in lst
lst.sort(item)
Sorts the items of lst in increasing

order






Methods append(), remove(), reverse(), and sort() do not return any value; they, along with method pop(), modify list lst

    • lst = [1, 2, 3]

    • lst.append(7)

    • lst.append(3)

    • lst

[1, 2, 3, 7, 3]

    • lst.count(3)

2

    • lst.remove(2)

    • lst

[1, 3, 7, 3]

    • lst.reverse()

    • lst

[3, 7, 3, 1]

    • lst.index(3)

0

    • lst.sort()

    • lst

[1, 3, 3, 7]

    • lst.remove(3)

    • lst

[1, 3, 7]

    • lst.pop()

7

    • lst

[1, 3]
Introduction to Computing Using Python    by Lj Perkovic





String operators






Usage
Explanation


x in s
x is a substring of s


x not in s
x is not a substring of s
s + t
Concatenation of s and t

    s * n, n * s  Concatenation of n copies of s

s[i]
Character at index i of s
len(s)
(function) Length of string s



To view all operators, use the help() tool


>> help(str)

Help on class str in module builtins:

class str(object)

|    str(string[, encoding[, errors]]) -> str

...





    • 'Hello, World!' 'Hello, World!'
    • s = 'rock'

    • t = 'climbing'

    • s == 'rock' True

    • s != t

True

    • s < t

False

    • s > t True

    • s + t 'rockclimbing'

    • s + ' ' + t 'rock climbing'

    • 5 * s 'rockrockrockrockrock'

    • 30 * '_'

'______________________________'

    • 'o' in s True

    • 'o' in t False

    • 'bi' in t True
    • len(t)

8
Introduction to Computing Using Python by Lj. Perkovic





String methods





Usage
Explanation


s.capitalize()
returns a copy of s with first character

capitalized


s.count(target)
returns the number of occurences of

target in s
Strings are immutable; none of the string methods modify string

link


s.find(target)
returns the index of the first

occurrence of target in s
s.lower()
returns lowercase copy of s
s.replace(old, new)
returns copy of s with every

occurrence of old replaced with new
s.split(sep)
returns list of substrings of  ,

s

delimited by sep
s.strip()
returns copy of s without leading and

trailing whitespace


s.upper()
returns lowercase copy of s
Programming Exercises




rpmaximum


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