Xiang Lian The University of Texas – Pan American Edinburg, TX 78539 lianx@utpa

1. CSCI/CMPE 4341 Topic: Programming in PythonReview: Exam I Xiang Lian The University of Texas – Pan American Edinburg, TX 78539 lianx@utpa.edu

2. Review • Chapters 1 ~ 4 in your textbook • Lecture slides • In-class exercises

3. Review • Multiple Choice • True/False Statements • Programming • Find bugs • Write the code • Bonus Question (20 extra points)

4. Chapter 1: Introduction to Python • Basic components in a computer system • The evolution of programming language • Structured programming • Object-oriented programming • Can you list several differences between C++ and Python? 

5. 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

6. Chapter 2: Basic Concepts in Python Programming • Commonly used Python rules/functions • # • print() • input() • int() • id() • type() • Escape characters • Arithmetic operators and their precedence • String formatting

7. First Program in Python: Printing a Line of Text • Python • The # symbol • Used to denote a single line comment • The print function • Used to send a stream of text to be output to the user • Executing • Saving as a file • Type code into a .py file and save it • To run it type python fileName.py • Executing code • Type python in the command line • Runs the python interpreter "//" or "/* … */" is used in C/C++/Java • "printf" or "cout" is used in C/C++ • "System.out.println(...)" in Java

8. Examples of Escape Characters

9. 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)

10. Precedence of Arithmetic Operators

11. # Fig. 2.19: fig02_19.py # String formatting. integerValue = 4237 print("Integer ", integerValue) print("Decimal integer %d" % integerValue) print("Hexadecimal integer %x\n" % integerValue) floatValue = 123456.789 print("Float", floatValue) print("Default float %f" % floatValue ) print("Default exponential %e\n" % floatValue ) print("Right justify integer (%8d)" % integerValue) print("Left justify integer (%-8d)\n" % integerValue ) stringValue = "String formatting" print("Force eight digits in integer %.8d" % integerValue ) print("Five digits after decimal in float %.5f" % floatValue ) print("Fifteen and five characters allowed in string:" ) print("(%.15s) (%.5s)" % ( stringValue, stringValue ) ) Fig02_19.py

12. Chapters 3 & 4: Control Structures • The syntax of basic sequence, selection, and repetition structures in Python • Selection • if, if/else, if/elif/else • Empty statement: pass • Counter-controlled and sentinel-controlled repetition • while, for • break, continue • Augmented assignment • Logical operators

13. Control Structure • 3 control structures • Sequential structure • Built into Python • Selection structure • The if statement • The if/else statement • The if/elif/else statement • Repetition structure • The while repetition structure • The for repetition structure

14. Syntax of Control Structure total = total + Grade counter = counter + 1 if Grade>=60: print ("Passed") if Grade>=60: print ("Passed") else: print ("Failed")

15. Syntax of Control Structure (cont'd) if Grade>=90: print ("A") else: if Grade>=80: print ("B") else: if Grade >=70: print ("C") else: if Grade>=60: print ("D") else: print ("F") if Grade>=90: print ("A") elif Grade>=80: print ("B") elif Grade >=70: print ("C") elif Grade>=60: print ("D") else: print ("F")

16. Syntax of Control Structure (cont'd) Product = 1 while Product < 1000: Product = 2* Product for Product in range(1, 1000): Product = 2* Product

17. 17 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]

18. break and continue Statements • The break statement • Used to make a loop stop looping • The loop is exited and no more loop code is executed • The continue statement • Used to continue the looping process • All following actions in the loop are not executed • But the loop will continue to run

19. Logical Operators • Operators • and • Evaluates to true if both expressions are true • or • Evaluates to true if at least one expression is true • not • Returns true if the expression is false • Not required in any program

20. and Logical Operator

21. or Logical Operator

22. not Logical Operator

23. Chapter 5: Functions • Modules and pre-defined functions • importmoduleName • math • math.floor () • math.ceil () • math.cos () • math.pow () • … • random • random.randrange() • Syntax of user-defined functions • Recursive function • Default arguments

24. 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 )

25. 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

26. Examples of Floor and Ceiling • floor function: • math.floor(2.10) = 2 • math.floor(2.00) = 2 • math.floor(1.90) = 1 • math.floor(1.80) = 1 • ceil function: • math.ceil(0.00) = 0 • math.ceil(0.10) = 1 • math.ceil(0.20) = 1 • math.ceil(0.30) = 1

27. 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

28. Recursion • Method that calls itself • A recursive method solves only a simple problem (base case) • For any thing other than the base case, it calls itself with a slightly simpler problem • Eventually it becomes the base case for which it knows the answer

29. Default Arguments • Function arguments • Functions may commonly receive a particular value type • When this is true a default argument can be set • Must appear to the right of any other arguments • A default value can also be set • If passes a value then the default value is overridden

30. Good Luck! Q/A