$30
ITI 1120
Lab # 7
More programming with lists
1
Star/ng Lab 7
• Open a browser and log into Blackboard Learn
• On the le? hand side under Labs tab, find lab6 material
contained in lab7-students.pdf file
• Download that file to the Desktop.
2
Before star/ng, 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 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 (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
Programming Exercises
Do as many as possible (preferably all) of the following 13
programming exercises from your 3rd recommended
textbook. The first 7 exercises are mandatory (see the slides
to come).
Introduc)on to Compu)ng Using Python: An Applica)on
Development Focus,
2nd Edi/on, Ljubomir Perkovic
Some/mes the author uses a word “outputs” by that he
means “prints”
First recall from the next 4 slides, list (and few string)
func/ons and methods that you will need.
Introduction to Computing Using Python by Lj. Perkovic
List operators and func0ons
Like strings, lists can be manipulated with
operators and func0ons
>>> 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
...
Usage Explana0on
x in lst x is an item of lst
x not in lst x is not an item of lst
lst + lstB Concatena/on of lst and lstB
lst*n, n*lst Concatena/on 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
Introduction to Computing Using Python by Lj. Perkovic
Lists methods
>>> 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]
Usage Explana0on
lst.append(item) adds item to the end of lst
lst.count(item) returns the number of /mes 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
Introduction to Computing Using Python by Lj Perkovic
String operators >>> '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
Usage Explana0on
x in s x is a substring of s
x not in s x is not a substring of s
s + t Concatena/on of s and t
s * n, n * s Concatena/on of n copies of s
s[i] Character at index i of s
len(s) (func/on) Length of string s
>> help(str)
Help on class str in module builtins:
class str(object)
| str(string[, encoding[, errors]]) -> str
...
To view all operators, use the help() tool
Usage Explana0on
s.capitalize() returns a copy of s with first character
capitalized
s.count(target) returns the number of occurences of
target in s
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
Introduction to Computing Using Python by Lj. Perkovic
String methods
Strings are
immutable;
none of the
string methods
modify string
link
Programming Exercises