CSCI/CMPE 4341 Topic: CSCI/CMPE 4341 Topic: Programming in PythonProgramming in Python

Review: Final ExamReview: Final Exam

Xiang LianThe University of Texas – Pan American

Edinburg, TX 78539lianx@utpa.edu

Review

• Textbook– Self-Review Exercises– Quick Quiz – Exercises

• Time– 8am - 9:45am, May 14 (Thursday)

• Place– ENGR 1.290 (classroom)

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Review

• Lecture slides– Basic concepts in Python– Control Structures– Functions– Lists, Tuples, and Dictionaries– Introduction to Object-Oriented Programming– Graphical User Interface Components– Python XML Processing– Database & SQL

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Review

• Multiple Choices

• True/False Statements

• Programming– Debugging– Write the code

• Bonus Question

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Chapter 1: Python

• Python is a scripting language– It is not compiled as an executable file

• Python– Structured programming

• Divide and conquer

– Object-oriented programming• Class and object

– Data encapsulation– Inheritance– Polymorphism

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Chapter 2: Basic Concepts in Python Programming

• Arithmetic operators and their precedence

• Commonly used Python rules/functions– print()

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Arithmetic Operators

• Symbols– * # multiply– / # divide– % # modulus– ** # exponential– // # floor division

• Order– Operators are done in order of parenthesis, exponents,

multiply and divide (left to right), and lastly add and subtract (left to right)

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Chapters 3 & 4: Control Structures

• The syntax of basic sequence, selection, and repetition structures in Python– Selection

• if, if/else, if/elif/else

– Repetition• while, for

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Syntax of Control Structure

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total = total + Gradecounter = counter + 1

if Grade>=60: print ("Passed")

if Grade>=60: print ("Passed")else: print ("Failed")

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for Repetition Structure

• The for loop– Function range is used to create a list of values

– range ( integer )

» Values go from 0 to given integer

– range ( integer1, integer2)

» Values go from first up to second integer

– range ( integer1, integer2, integer )

» Values go from first up to second integer, but increases in intervals of the third integer

– The loop will execute as many times as the value passed

– for counter in range ( value ):

[0, integer-1]

[integer1, integer2-1]

[integer1, integer2-1]

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Chapter 5: Functions

• Modules and pre-defined functions– import moduleName– math

• math.floor ()

• math.ceil ()

– random• random.randrange()

• Syntax of user-defined functions

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Module math Functions

• Module– Contains function definitions and other elements

• All of which are related in some way

– Calling a function• functionName ( argument1, argument2 )

– The import keyword is used to include a module– Invoking functions from a module

• Use the module name followed by the dot operator (.)

• moduleName.functionName( argument )

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Random-Number Generation

• The random module– Used to generate a random number for the

programmer– Function randrange

• Generates a number from the first argument up to, but not including, the second argument

• Each number in the range has the same likelihood of being selected by the function

– random.randrange(a, b)

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User-Defined Functions

• Definitions– Functions must be defined before they are used– def functionName ( paramList ):

• functionName is a valid identifier

• paramList is a comma separated list of parameters received

• The actions of the functions then follows– They should all be indented appropriately

– The actions are also called the block or the function body

Chapter 6: Lists, Tuples, and Dictionaries

• Creation and manipulation of sequences– String– List – Tuple

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Example of SequencesC[0] -45 C[-12]

C[1] 6 C[-11]

C[2] 0 C[-10]

C[3] 72 C[-9]

C[4] 34 C[-8]

C[5] 39 C[-7]

C[6] 98 C[-6]

C[7] -1345 C[-5]

C[8] 939 C[-4]

C[9] 10 C[-3]

C[10] 40 C[-2]

C[11] 33 C[-1]

Name sequence (C)

Position number of the element within

sequence C16

Creating Sequences – List

• Lists– Use brackets

– Separate multiple items with a comma• list1 = [1, 2, 3, 4]

– Empty list• list2 = []

• Length of the list– len (list1)

• list1[0]=0 # OK!

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Creating Sequences – Tuple

• Tuples– Use parenthesis– Separate multiple items with a comma

• tuple1 = (1, 2, 3, 4)• tuple1 = 1, 2, 3, 4

– Empty tuple• tuple2 = ()

– Singleton (or one-element tuple)• singleton3 = 1,• Comma (,) after 1 identify the variable signleton3 as a tuple

• Error!– tuple1[0]=0

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Chapter 7: Introduction to Object-Oriented Programming in Python

• Classes– Attributes

• Private attributes• Class attributes

– Methods• Constructor: __init__• Get and Set methods• Destructor: __del__

• Objects– Creation of objects

• Inheritance

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Class Declaration

• Defining a Class– Class header

• Keyword class begins definition– Followed by name of class and colon (:)

– Body of class• Indented block of code

– Documentation string• Describes the class• Optional• Appears immediately after class header

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Class Declaration (cont'd)

• Defining a Class– Constructor method __init__

• Executes each time an object is created• Initialize attributes of class• Returns None

– Object reference (self)• All methods must at least specify this one parameter• Represents object of class from which a method is

called• Called self by convention

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Get and Set Methods

• Access methods– Allow data of class to be read and written in

controlled manner– Get and Set methods

• Allow clients to read and write the values of attributes respectively

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Destructors

• Destructors– Method is named __del__– Executed when object is destroyed

• No more references to object exist

– Performs termination housekeeping before Python reclaims object memory

• Typically used to close network or database connections

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Chapter 8: Graphical User Interface Components

• Components– Label – Entry– Button– Checkbutton & Radiobutton

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Entry Component – TextBox

• Textbox– Areas in which users can enter text or

programmers can display a line of text– Created by Entry class

• <Return> event occurs when user presses Enter key inside Entry component

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Checkbutton and Radiobutton Components

• Checkbox– Small white square – Either blank or contains a checkmark– Descriptive text referred to as checkbox label– Any number of boxes selected at a time– Created by class Checkbutton

• Radio button– Mutually excusive options – only one radio button selected

at a time– Created by class Radiobutton

• Both have on/off or True/False values and two states – selected and not selected (deselected)

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Chapter 9: Python XML Processing

• XML documents– Tree structure – Tags– Elements– Data

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Chapter 10: Database & SQL

• Relational database– Database schema– A set of relational tables

• SQL (Structured Query Language)– A database language– Syntax of SQL

• Use Python to submit SQL to databases

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Example of Table: Employees

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SQL

• A program might select data from the table to create a query result – E.g., to retrieve the location of each department, in

increasing order by Department number

– SQL: • SELECT DISTINCT Department, Location

FROM Employees

ORDER BY Department

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SQL Results

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SQL on Books Database

• SELECT * FROM tableName– SELECT * FROM Authors

– SELECT AuthorID, LastName FROM Authors

• SELECT columnName1, columnName2, … FROM tableName WHERE criteria– SELECT Title, EditionNumber, Copyright

FROM Titles

WHERE Copyright > '2014'

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Example of Using pyodbc Packagehttp://en.wikibooks.org/wiki/Python_Programming/Dat

abase_Programming

import pyodbc DBfile = '/data/MSAccess/Music_Library.mdb'conn = pyodbc.connect('DRIVER={Microsoft Access Driver (*.mdb)};DBQ='+DBfile)#use below conn if using with Access 2007, 2010 .accdb file#conn = pyodbc.connect(r'Driver={Microsoft Access Driver (*.mdb, *.accdb)};DBQ='+DBfile)cursor = conn.cursor() SQL = 'SELECT Artist, AlbumName FROM RecordCollection ORDER BY Year;'for row in cursor.execute(SQL): # cursors are iterable print (row.Artist, row.AlbumName) # print row # if print row it will return tuple of all fields cursor.close()conn.close()

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Good Luck!Good Luck!

Q/AQ/A